I have a second N900 which is almost a clone, that is, it was a clone up to two weeks ago, but on my everyday device some additional programs have been installed like mypaint, OMP and a game or two.

The everyday device runs Thumb2 v.1.4, the spare one that I don't use runs KP50 with CSSU-T v.1.2. If needed both devices can be brought to an almost identical state, by installing the missing apps if needed on the spare one.

In short: If the above is good enough for the OP, I'll run some tests and post the results here.