Is it okay to go to a cake tasting at our baker after we've picked flavors?

Ask them. It's seems like a reasonable request. If you're already under contract, they might ask you to pay for it. Bakers I researched charged $25-40 after the first tasting. So second tastings are not unheard of.

I agree! Explain your situation and ask. I used to work at a very fancy bakery and a tasting was $25 there. If they do ask you to pay it probably won't be a lot.

Totally reasonable.
My fiancé is my baker and he knows what I like and we still did a tasting lol plus what of something has changed and you want a different flavor? Totally reasonable to want a tasting.

I feel the exact same!! I picked our wedding cake flavor back in summer 2020 via no-contact cupcake tasting to-go my fiancé never got a chance to try because of the old travel bans. Even though it would be too late to actually switch anything when we arrive in the States the week before the wedding, I still want to ask if I can swing by and get a little box of all the bites and a cupcake of our cake flavor for my FH to try... and for me to remember! We also didn't try any of the bites we're going to serve! Just go do it, it'll be fun.

I would do a Second tasting!

I would go for a 2nd tasting just ask,