Chassis Dyno? (New Prop)

Just ctrl-middle mouse car to dyno frame, or the ground, does it need much more?

Rollers could have convex shape, or what it was called, where center of roller is slightly smaller diameter than edges, so car centers better.
However grip and steering might provide some issues. It is far easier to just have long gearing, strong brakes and torque converter, using that it is relatively easy to set up turbo.

Especially now that I got turbo torque spreadsheet working bit better again, so it is quite little fiddling that is needed anymore, just how turbo spools up (that is compressor map, exhaust power) as amount of power is copy paste job. There is still need to improve many aspects, but considering how difficult it was to achieve even somewhat there tune for a turbo car 1 year ago and what it is today, miles of difference.

I would say that any rolling road will be more of coolness and great feeling to do a dyno pull, but it would probably have challenges in how controllable it is. Measuring would still be done like now, because measurement from some kind of roller, that would be really challenging, there would always be some slipping.

So while I do understand desire to have a 'real' dyno, I doubt it would provide much more usability to tuning turbo engines as we have all the control already available.

Well, UI app to control TC size on the fly or automatically to keep rpm constant, would be nice, you could adjust throttle and TC size would change on the fly to keep rpm same, if someone wishes to put effort to dyno, that would probably give best return on invested time.