I've done a special version of the firmware without fuel cut enabled for the DPR
this should allow you to set the DPR in VE without having the engine running
just make sure you only use it for testing and swap back to 5.5.6 to run the engine
microsquirt_noDPRFuelCut.zip
The red zone is classified under "That's an awful lot of tune correction"
the system is deliberately restricted to +/- 200mA which is well within the happy range of the DPR
working range should be somewhere between -7mA and +130mA or 93 and 230 in the VE tables plus adders such as warm up and trims
255 is the maximum you can put in the VE table