Butter poached shrimp
How many portions are you estimating selling? I would cook them at the last minute before service(even better in batches throughout service) then hold them in a 6th/3rd/whatever pan full of beurre monte that's sitting in a warm water bath and give the plate a quick flash in the salamander before saucing, garnishing and serving.
In my restaurant I'm doing a butter poached Maine lobster for new years. I'll have a couple induction burners set up with clarified butter at a constant temperature. We'll do 300+ covers and I'm expecting at least 40 to be lobster. I'm going to put the lobsters in there 3 at a time. As soon as one goes out, one goes in. The most important thing is timing. With three, if they sit too long, I won't risk ruining a lot of them. Chances of that though won't happen. If I have three in, and I get 7 orders at once, I'll drop 7 more to sell the 7 and have three extra for the next couple tickets coming in. Towards the end of the night is when things slow down and I'll do them to order where time is allowed.
If you're tickets are going to be flying out the window when they ring in on hot orders, I would marinate the shrimp in an acid almost like ceviche if the flavor pairings allow for it before service. That way you can just hurry and warm it up in the butter and not worry about anything being under cooked. But like others have said it only takes just a few minutes. You should have no problem with it.