Yes - I have specified 1.6mm standard PCB for these. The reason is that going to 2.0mm PCB adds about $20 each to the cost of each PCB, this was not the case a couple of years ago. Initially I decided to order 1.6mm while prototyping only but I found it was actually stiff enough, supported by the full-length claw at the bottom of the case top.
Unfortunately it is not possible to switch the KS-33 low-profile switches into the old PCB, as the footprint is different. Also it is essential to use a printed plate with these switches as they do not have the extra mounting pins (3-pin rather than 5-pin style) to locate them exactly.
The v2 keyboard is a little neater in appearance, and has the keycaps at a much better (lower) height with respect to the top of the case - it looks the height an Amiga keyboard should be, v1 is a little taller. It has the multi-color power led that provides caps lock function, and you don't need the separate LED circuit board. I personally prefer the low-profile banana switches to anything else on the market at this point. But there is nothing wrong with the first version of the keyboard, some people will prefer the full-height MX switches and they should stick with v1. They use the same keycaps so you could have both and switch between if you want.