With Mayweather's fragile hands does anyone really think he'd compete wearing 4oz. gloves? I was surprised he agreed to 8oz. gloves for the Mcgregor fight, and I don't see how he doesn't break them in 4ozers. And of course defensively the larger the glove the more it favors Mayweather.
And NO I don't think Mayweather even competes in the UFC. A UFC PPV wouldn't generate the same amount of revenue as a boxing match would (say 3.5M buys @ $50each = $175M + another $75M from the gate & cage sponsors and the total revenue before salaries, expenses, profit, overhead, etc. is less than half what the Pacquiao fight generated).
Mayweather earned something like $25M just on sponsors on his shorts, robe and caps for the McGregor fight. Is the UFC suddenly going to let Floyd have his own sponsors when they strictly forbid it for everyone else?