You're very welcome, Pete!
Thank you so much for this wonderful feedback!
Yes, I was aware of your late hours, and I hope that the rest of the project will work out nicely without long evening hours.
I have left the Attribute Manager > Mode > Scene > Simulation> Scene Scale as you had it. (Many times "Scene", but that is the path) Since it was cached, I haven't made any changes. (Yes, I tested it with a 5cm scale, and got indistinguishable results compared to yours. So I left it as is.)
This is perhaps more for after the deadline to explore, but just in case:
There is a little bit of "jitter" in the spline. I have marked the three elements in Pale Blue (layer chips). Since the whole "group" moves. I was not able to place it inside (it would receive twice the motion), so it is on top.
The idea is to produce a copy of the spline, mainly to add the Delay Effector to it, and with Blend to limit the jitter. I'm not clear how that will affect the hand animation synchronization. But just in case things are needed.
https://projectfiles.maxon.net/Cineversity_Forum_Support/2025_PROJECTS_DRS/20251021_CV4_2025_drs_25_SIha_11.c4d.zip
Here is a simple version of it.
CV4_2026_drs_25_ANnt_01.c4d
My best wishes!