Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

Spell Focus Conjuration improves Summons.

Spell Focus Transmutation improves Shapechanging.

And Spell Focus (Necromancy) Improves Undead summoning.

Why not allow Spell Focus (Abjuration) to add non-cumulative bonuses on Dispel checks? +1, +2, and +4 respectively. Apply to all dispel effecs, Mord's Dysjunction etc.

In addition: Spell Focus (Abjuration) adds a +1 to the Die Result when casting Spell Mantles for the number of spells it can absorb. This improves to +2 for Greater, +4 for Epic. So for example a Greater Spell Mantle cast by a caster with Epic Spell Focus (Abjuration) would absorb 1d12 + 14 levels worth of spells instead of 1d12 + 10.

Thoughts? Opinions?

I definitely think that Spell Focus line for abjuration is in need of some love. As of now, per the wiki, there are 90 abjuration spells listed, a few of them doesn't have a mechanical function or simply don't work but still over 80 I think, if those were not counted. Only 12 of them allows a saving throw against a DC -8 if you compress that list by condensing lesser/greater versions of the spells.

In my opinion amongst the listed suggestions, I like the spell mantle one the most. I feel like it's more in align with the defensive nature of the abjuration school.

I think this is a great idea, and I would add that every spell focus should grant small bonuses beyond +1 to DC in that school, although I worry about the excessive power of the specific bonuses suggested in the OP relative to those given by other focus feats.