My custom boot story has an ending now: I gave up. I suspect the root of the problem with my SP-Teris was that they don't have any padding whatsoever in the bottom, nor room for it. (Even after my sales rep took a dremel to the ball area to carve out a little more vertical room so I could slip a very thin Dr. Scholl's-type insole in there, it didn't work.) That's on me; I didn't realize there was just nothing in there but a thin piece of leather, or I would've thought much harder about going with SP-Teri. I have a hard time with shoes that don't have much of a padded insole too.
In addition to the many, many modifications my sales rep made (the man is a saint!), I sent them back twice with unsatisfactory results. The first time, it was because they were half an inch too long; I asked for them to cut down the length but leave the width alone, and also to snug up the heels. I got back a shorter, narrower boot that was just as sloppy in the heels as before.
Okay, whatever; I punched out the front and padded the back. Now my feet were going numb from the arch to the ends of my toes within ten minutes of putting them on. After much punching, stretching, lacing modifications, ankle sleeves, pads, arch supports, etc. etc., we ended up taking a cast of my feet with those casting socks and sending them along with the boots, with a note/phone call that basically said "Please make these look like the casts! Also I think making the tongue wider would help, given my instep/arch issues." They told me it would be really difficult to make a wider tongue as that requires cutting a new upper, so instead they just widened the ball and toe area a bit more. (You know...to where I'd asked them to keep it last time...)
When they came back and there was no improvement, I threw in the towel. It's now been nine months since I first got them, and I just want to skate. I have an appointment with the local Jackson dealer tomorrow morning. My old ones were far from perfect, but they were better than this. I've learned my lesson to never buy a new brand without trying on a pair of their stock boots first.