At this point, you only have one 5th level slot and between synaptic static and animate objects, you should be able to use that slot effectively. If you take a 5th level spell for your magical secrets, you are taking it to save for later more than to use now. I normally suggest find greater steed but if you don't think that's a good choice for you, then don't take it.

As a bard, you likely have a lot of concentration spells. Hypnotic pattern, hold person, heat metal, polymorph and animate objects have been mentioned. I assume you have silvery barbs for a reaction defense, vortex warp and dimension door for movement, and raulothims psychic lance for 4th level non concentration debuff. If you don't, I'd swap out bard spells to get those if you can.

For your magical secrets, I would consider taking Tasha's mind whip. It's a very good concentration-free debuff that I can't believe isn't on the bard spell list. It's a good use of 2nd-4th level spell slots, upcasting to affect more targets.

Pass without trace is a great spell for the party to have. For a bard, defensive spells like shield or absorb elements can be useful too.