1D is one of those great clues where the surface is so coherent and the answer feels like it has nothing to do with it at all.
4A is probably my favorite. "game of chance" is seamless, and I'm obsessed with clues where the deletion is clued with a synonym, "painlessly" for [-ow].
My one question is with 6A, I'm just not familiar with the definition. Am I right assuming it's like a "drag glow-up" or something like that?
Yeah, "drag up" is a newish term used on RuPaul's Drag Race (similar to "spice up"). This is my least favorite clue, especially since "up" is sort of there twice, but I wanted to take a shot at the term. Glad you liked the rest!
1D M+ADDER
2D [-w]EBBING
3D R(EW)RAP<
4A GAM(BL[-ow])E
5A REGI[-ci]DE*
6A UPGRAD[-e]*