Ziggy's weird little white growth on his tongue turned out to be just a papillomavirus wart after all. I could go back an forth in hindsight now and wonder if I should have taken him to my regular vet before subjecting him and my pocketbook to surgery, but it's possible that vet might have also suggested surgery, who knows? And if the wart didn't go away like they're supposed to I'd probably always worry a little anyway and for the time he had it, because who knows how long it would be there, I'd be worrying. And worry is stress and stress can cause heart attacks so I probably did the right thing after all.
His tongue looks really good now, too.