Some examples.

The obvious thing is to give everyone in the party familiars. Then you can break the concentration economy by having familiars concentrate on spells for you.

Most broken idea: Assuming you have catnap prepared, you can take a short rest at the cost of a level 3 spell slot – and that short rest lasts only ten minutes. Then you can have multiple Arcane Abeyance beads prepared at once. Assuming you have the spell slots to burn (on catnap and the spells), you could theoretically store up to five concentration spells in beads, which you can have a bunch of party members launch simultaneously. Now, obviously this requires a lot of planning and careful timing, but assuming you also cast one spell normally, you could open combat with a surprise 6x save-or-sucks and burn all legendary resistance quite easily. Obviously, if other party members are casters with their own save-or-sucks, then this becomes easier to set up and you can burn fewer spell slots/catnaps. What’s the optimal spell here? I don’t think you could stack 6x sickening radiance on a square, for six saves per round, but maybe…

And there’s the classic wizard microwave combos that would normally require two wizards to pull off: wall of force plus sickening radiance or something (have your familiar concentrate on one of them). I’ve seen suggestions that Mordenkainen’s Private Sanctum in combo with Wall of Force is a good choice, since it also prevents them from teleporting out. Any other good microwave combos?

And there’s combat casting of spells that would normally not be combat castable: leomund’s tiny hut, hallucinatory terrain, conjure minor elementals, etc. What’re the best out of combat L4 or lower wizard spells that could be even more powerful if used in combat?

Hell, giving a shadow blade to party members in general. What wizard spells would other party members really benefit from having?

Anyone play in a party with two wizards? What combos worked well?