I think it is fisible with module 0.7 cutters. The center to center distance for the DP40 (module 0.635) gears is 33.34 mm if you make a module 0.7 pair with 32 and 64 teeth, you end up with 33.6 mm center to center disance.
My guess is that you can squeeze out the 0.6-0.34=0.26 mm center distance, using profile shift. Blanks a litte undersized same cutting depth.
The alternative would be helical gears. Adjusting the helix angle to get desired center to center distance. In that case it would result in a pair of 31 and 62 teeth with module 0.7 and a helix angle of 12.5°. Provided I did not miscalculate, this will result in center to center distance of 33.34 mm.
Non standard module cutters work same as standard ones, as L98fiero explained. (Module 0.635 is conversion from 40DP, so some people would even consider this standard
as well)
Down side of "non standard" is that there are no cheap cutters that can be bought. And it cannot be combined with commercial gears. (In that context "non standard" means not DP and not metric module, or some very weird pressure angle.)
Greetings Timo