The Esc pack is an interesting idea, I would probably get a set if you end up doing it. The yellow WASD cluster isn't very appealing to me. Also I noticed that there is no R2 1.5u Backspace key for HHKB type layouts.
I have that as a question in the OP. Should I add an R2 1.5x Delete and R1 1x |/ key? The main reason I didn't is because the Viper is the only board off the top of my head that supports the HHKB layout, so it didn't make sense to add it for such a tiny minority who probably aren't buying it, at least not for the Viper.
Any caps that can be nuked to make it more affordable?
To make it more affordable, maybe remove the alternate arrow cluster and one of the WASD sets? Limit stepped Caps and R3 Control to one color?
I could delete the one WASD cluster if there's a general consensus for blue or yellow being preferred, but the alt arrows are likely staying for those who want uniform mods.
Similar deal for the stepped and full touch caps, getting rid of them disrupts some winkeyless boards. If there's a way to reduce the number of caps and control keys without disrupting compatibility, I'm all for it.