I delivered my first Chroma to another photographer last night and, apart from never using "flourescent blue" acrylic again, it went well :0) I'd added extra light seals to the front and rear standards to block unwanted light but found that the acrylic manages to bend light around corners
After a bit of adjustment of the seals and several rounds of swearing at 11pm (it's being used on a commission in Birmingham today!..) it's good to go.
My main findings from the completed Chroma are;
1) Never use flourescent acrylic again...
2) Remove the build complexity of the front standard to simplify its assembly and use
3) Swap out the sliding foot that the front standard is bolted through and replace it with several fixed position threads on the focusing bed. There's 0.5mm of play on each side of the foot from where it was cut out of the surround piece that's used as the focus rail. On its own that's not a problem but when I add the wide front standard, the extra torque means that there's some wobble even when fully tightened which isn't ideal
4) Use metal 90 degree brackets to bolt the rear standard to the camera bed because the current acrylic brackets are a potential weak point when the camera is folded.
5) Use smaller magnets to secure the ground glass holder. On previous builds I've used four 5x5mm magents on the rear standard and six on the ground glass (it's moved between two positions). For this build I swapped to four 10x5mm magnets on the rear standard and six on the ground glass and they're ridiculously strong!
Overall, no major changes needed but they will all add up to improve the complete handling/assembly.