When I switched from my Riedell Royals to my Jackson Elites, the heel pitch on the Jackson was definitely greater than on the Riedell. A greater heel pitch shifts my weight forward, towards the toepick. When skating backwards, I need to lean backwards more to compensate, to shift my weight back, away from the toepick. To me, that scenario is consistent and logical.
And yet that can't be completely correct. I know you know enough physics to get this. The heel pitch does not "force" your weight forwards - because of newton's 3rd law (or its equivalent in torques), that would push the heel of the skate downwards, rolling the blade along the blade's rocker curve. But for a static skater (no internal motion), balance only occurs if the center of gravity is over the base of support - i.e., that which touches the ice - a very small spot, a few mm wide, by a few more mm long. Your weight must therefore be further back to be in balance. It's very simple physics. When you are in static balance over such a small point of contact, there can be no net torque, and nothing is forced in that way.
So I think you would still find that shimming the back of the blade would solve that problem - even if I am wrong and the average
higher on the new boots.
If you don't believe me, try making the correction temporarally INSIDE the boot, which is very easy and fast to do. Place something under the heel of the insole. I bet it pushes the back of the boot down a little, forcing your balance back. Of course, if the boot is very snug, there may not be room...
Also, the profile of the footbed is not a constant pitch - it is a much more complex 2D curve. Different parts of your foot (which is reshaped by the footbed and your weight on it in complex ways) apply a torque to the boot when you are not in balance, until you are, though of course that gets more complicated with dynamic balance, when your body configuration is changing, or you are rolling forward or back. So, the average pitch, or the pitch at some point doesn't tell the whole story - all that matters is the net torques that roll the blade until the net torque is zero - which on a skate, creates the effective heel height, which matters more than the real heel height. (OTOH, when I got my Klingbeils, the real heel height, and the bend at the ball they created to balance it, was so great that it hurt my feet to be in the boots. That mattered too, but was a seperate issue. I hate high heels.) In other words, when I said the (effective) heel is higher or lower, that is a great simplification. I am more concerned with how to correct it than with an actual measurement of heel height.
There are other explanations - e.g., the place the blade is mounted, and the way your foot projects vertically into the ice. I will start with the assumption you are using exactly the same blades (and not just a similar pair of blades) - otherwise this whole discussion is meaningless. E.g.
1. Assume that the blade is mounted further forwards - relative to the vertical projection of your foot
. Then it is easier for the toe pick to touch. This can easily occur if you mount the blade according to the position of the outsole, rather than relative to the projected foot.
2. Assume that the vertical projection of the foot is shorter, taking into account not just the average slant, but the full profile of your foot inside the boot, which bends your foot in various ways, especially at the ball. In principle, a shorter blade might have solved the problem.
3. The shape of the new boot allows your foot to slide forward and back a bit. So, when skating forwards, you slide forwards, which means you balance farther forwards along the rocker then before, pushing the toe pick into the ice.
4. A very possible explanation would be that there is a sharper bend at the ball of the foot in the new boots - or even worse, the bend is too far forwards, and bends your toes instead of the ball of your foot. That exerts a net torque fowards of the balance point, until the balance point rolls forwards, pushing the toe pick into the ice.
5. Maybe the arch of the new boots is higher or lower, changing the shape of your foot in such a way as to cause the differing balance. For example, a lower arch would cause your foot to collapse more under weight, pushing the toes a little further forwards, and maybe the heel a little further back - and vice versa for a higher arch.
6. Maybe you can come up with other similar potential differences.
What has eluded me, as well as others I've talked to who have experienced this, is why there is a much more pronounced effect when skating backwards than forwards. I realize that you skate on a different portion of the rocker when skating backwards than forwards, but I would expect a higher heel pitch to also require compensation for forward strokes too, but that doesn't appear to be the case.
Which could mean something is wrong with your theory.
It might also mean that you have learned to compensate for the toe pick when skating forwards, but not backwards. E.g., maybe you unconsciously flex your ankles, raising the toes, when skating forwards.
Another possibility, which does mess up my static skater theory, is that you might roll the pitch of your foot from the back to the front as you skate forwards - and you have unscouncsiously learned to stop the roll before the toe pick touches. Maybe you adapted that very quickly to the new boot.
In contrast, when you skate backwards, maybe you have not had to start that reversed roll (from back to forwards - or maybe you don't roll when skating backwards) at a different point. But with the new boots you need to.
Or - maybe your heel fits more or less snugly in the new boots, so the back of the foot doessn't press against the back of the boot the same way.
Or - when you skate backwards, your weight on the medial arch of your foot is greater, and it collapses more (this may vary by personal anatomy) - pushing the toes further forwards.
There are so many variables, it doesn't really matter. What matters is what you can do to correct it. If you are happy with changing the way you skate, fine, as it sounds like. If you want to use an equipment approach, fine too. I believe my shimming approach is still sound. But you would have to test it to see.