I knew to change the 2nd special offensive flag set like that because Nayru's Love, PK Fire, MK/Kirby's Nados, etc that didn't have the correct amount of hitlag (generally none) based on their dmg and hitlag mult had a number besides 0 in there like every other SOC (usually a 2 but sometimes a higher number). It might either set the hitlag to a specific value (2 in most cases) or divide the hitlag by the number when included, both of which don't work well with the 60% B+ hitlag code. I never really checked to see exactly how it modifies it.
On that same set of SOC flags, I know that xx4FFFC0 allows reversible KB as normal, but xx4FFFC3 and xx4FFFC4 don't. Don't know the specifics here either.
On the 1st set of SOC flags before that one, it sets the refresh time of the hitbox (to not refresh it has 00000000). If for example it's set to 8, the hitbox will refresh itself 8 frames after the last time it hit the target and be able to hit them again as long as the collisions haven't yet been terminated. If the hitbox were out from frame 10-36 and hit them on frame 10 to start, it would hit on 10, 18, 26, and 34. If it 1st hits them on 14, it'd hit on 14, 22, and 30.