Various statuses on the shield bash could open up a lot of different combat choices, such as a fire bash on ice cubes or a poison bash on gremlins. The only problem is that the shield bash, while an offensive attack, is one of the most vulnerable attacks in the game. Shield bashing into a group of enemies to clear a way through is fine and all, but if they aren't stunned then they'll likely land a hit on you.

If other statuses were implemented, the shield bash would need a much higher knockdown/flinch rate, or additional combat attributes (such as knockback on tortoshield bashes).

I would recommend not having these be UVs due to the issue of wanting a stun shield bash and crafting an item with a fire UV, rerolling it and getting freeze, then fire, etc. Instead I would recommend having certain item's shield bashes granting different status effects, or alternatively giving players a trinket that aligns damage to deal a certain status, and would stack like defense UVs (+4 is maximum). Each 5* trinket would grant +2.5 (or whatever puts it in line with other defensive trinkets). At +1, all non-status charge attacks have a chance to inflict a status. At +4, all non-status charge attacks have a high chance to inflict status. At +5, all non-status standard attacks have a chance to inflict a minor status. At +8, all non-status standard attacks have a moderate chance to inflict (minor) status, and charge attacks can inflict moderate status. Same-status weapons stack their status intensity (i.e., +8 stun makes fearless rigadoon inflict stun a lot).

Then throw the +2 bonuses on various pieces of equipment, and treat the shield bash as a "charge attack". Bam, status shield bashes that you have some level of control over.