BTW, I've used pro-filers for years on stainless steel
old style Matrix blades for many years (440 or 440C alloy). They work great. Also on high carbon JW Coronation Ace and MK Dance.
Trace the rocker profile first, so you can maintain it. And, just in case there is a slight asymmetry, take a few strokes, flip the blades (or Profiler) around, take a few more, and repeat.
If you don't use tape, oil or water the sides of the blades to avoid scratches. If the gap is too narrow for your blades, file it wider as symmetrically as possible - but some old Pro-Filers had an adjustable set screw.
Lubricate your stones with water. Oil works too, but is messy in your bag. Use the coarse stone (diamond dust abrasive) as much as you can - it wears out a lot slower than the fine stone.
Since the old used
Berghman sharpening tools (that search was on U.S. eBay - I don't know how to search for used gear in your country) are so cheap, I would use one instead of the Pro-Filer handle to hold the Pro-Filer's abrasive cylindrical stone, on the 1/2" pair. Better control, and you can get closer to the toe pick. Plus, you won't need tape or filing, because the gap width is adjustable - though you should oil those adjustable jaws to avoid scratching. But they only hold 1/2" stones. I once tried to wrap a lot of tape around a 3/8" stone, but that was just a mess, and it moved around too much. I really, really wish someone would start making them again, in other ROH's - the patents have expired.
I personally think you made a great decision to use parallel sided blades. Some people claim other blade shapes have advantages, but parallel sided blades are so obviously easier to deal with.
Supersharp's suggestion that you get a second pair of boots sounds good - but if you don't trust any skate techs there, I don't see how you could find one who could fit boots to you well. And maybe the skate tech she knows will solve the whole problem. Can you adapt rental skates? By making your own insole?