Mine own (and slightly off) perspective. . .
At my first take at a wedding (which led to domestic partnership, not marriage), I made kilts for both grooms, both best men, and both ring boys. Wedding-Take-Two was a hurried affair with several other couples once legal marriage was opened up -- and it was held during our church service. Due to the fact that I sing in the choir (and didn't own a black kilt at the time), I was in our choir uniform of black pants, and white shirt. My best man was able to attend the service on the extremely short notice. He wore the kilt I had made for him for our (first) wedding. He was the only kilted one in the church that day. And when we (my husband and I) saw him (my best man) walk in we were both extremely honored that he came not only in a kilt, but in the kilt I had built him for our wedding.

So before assuming you will upset the wedding party, they might find it an extreme honor that you took the time and care to wear the kilt and wear it with pride.

Cheers
Chris