Acoustic Guitar Construction

I am about to start on a hybrid guitar. An OM with a cutaway, slotted head stock, V-class bracing and nylon strings. Most of it I've figured out, but I am in doubt about the saddle compensation.
The Spanish guitars I've played have no compensation on the saddle, but are without exception sharp on the 12th fret on the low strings. I tend to use some sort of compensation, but how much?
Anyone has an idea? John?
Herman

I do 2 mm straight across. I sometimes do .7 mm of nut compensation; then I do 1 to 1.5 mm saddle compensation. My saddles are 3 mm (more room to compensate the bass). Some nylon string builders use 2 mm.

Thanks mate, That helps
Herman