Recently my group went through a harrow deck of many things reading and one of them pulled the mountain man card which increases your size by one step. Originally I thought that the enlarge person spell effects would effectively be made permanent on him, but after doing some flipping I'm not so sure as there are numerous inconsistencies regarding size modifiers to ability scores.
Do I use the Bestiary's table for monster size advancement (+8 Str, -2 Dex, +4 Con, +2 nat armor), or do I use the Giant Form spell, or enlarge person spell.
Where are the definitive size modifications to ability scores located?
"Use the bestiary table unless the effect specifies otherwise" is probably the best rule to use.