The VOIDRUNNER'S CODEX is LIVE! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
Odds are an NPC you are creating for a supplement uses rules for the supplement that (unless you are the programmer of the tool) can't be supported before you release the supplement.
For (potential) publication? By hand, or both (to compare results). Somehow I don't trust those programs that much... but it's always good to double-check.
Only if the NPC is for my homebrew and the stats aren't that important I'll use a program...