Multi-Classing

[7thGate]

Why wouldn't you? Bards being able to cast things on the move is a default class feature.

Other possibly good options:
Level 3 Rogue for Hide/Sneak
Enchanter levels to get Rod of Annihilation access on a melee in addition to Lull/Gate/Stun/Mez. You would see a lot of Enchanter 4 I think, like Paladin 2 in pathfinder 1st e.
A warrior level for better armor access.
A paladin level on a rogue to backstab with Great Spear of Dawn.

Splashing a level for gear proficiencies is extremely common in PnP RPGs that allow that kind of behavior. There's a lot of gear that's balanced by not being accessible to certain classes which would be worth losing some of the capstone class abilities to get.