How much adv with 50/50 mix

[tweeqd]

I know its proably to gerneral and will change from engine to engine
Im looking to run the dds3-v10 on my engine and tune the ign to make the most of the meth
The fail safe will switch maps in my DTA but the second map is already tuned for nitrous (not used on the road) the nos map has about 5 degrees of ign taken out of the standard map so is this going to be enough as a failsafe
As in if it takes another 5 degrees of ign with the meth is the 10 degrees retard going to be safe should i loose water/meth


Thanks martin