It doesn't seem to account for that much, but it does discuss the difference between MW2e's adventure points and skill points and that APs convert at a 1:1 ratio and SPs at a 5:1 ratio. That doesn't help me much though, since I'm working from fixed stat blocs in a book - I don't have any idea what APs or SPs were used in those builds. I was somewhat mindful of the background skills and began with the standard 850 XP expenditure for life stage 0 and gave my converted NPC the Language, Perception & Protocol skills which the MW2e stat block didn't have.
That still ended up with an AToW NPC that was woefully underskilled, so I increased the 2 attributes they had at 6 to 7 (7 of their 11 MW2e skills after conversion were linked to them) and increased a number of skills a level or 2. I also brought their 2 advantages/traits up a level to 2. That still left me with about 700 XP remaining, but the NPC is at a point where if I added more they'd risk becoming OP.
AP were used for pretty much all advancement, SP were only used for skill advancement
so lets say your char has a skill at level 4 that they want to advance to 5 they would normally spend 10 sp, and 6 ap and they now have level 6 if they have a trainer (someone who already has a level 6+ in the skill and training
they can also advance it by spending 12 ap or 10sp plus another 60 sp (if they have TONS of sp that they don't know what to do with)
I want to say advancing without a trainer cost double ap but I would have to reread that portion
to advance an attribute cost 2x the ap of the level of the new stat, or it was 10x with ITN (intuition) costing double as it always cost 2x as much as any other stat because most things tied back to it.