I learned whils trying to build a swashbuckler (Dex/Cha based) that buckler's and light shields are not finessable this makes no sense especially in the context of a swashbuckler.
I mean their light enough to use evasion with (see "Armor Up" changes) so it makes sense that they should be finessable.
Edit: Apparently IC:Bludgeon doesn't work either, it should