Some people regard it as dirty to grab someone else's RB handcuff, but I have no issue with it.

My opponent can have a second QB while I spend a roster spot on Mason. McCaffrey's health has been in question for weeks.

I have Pacheco in my active lineup and stashed Clyde Edwards-Helaire for my bench. He should be the backup once he's healthy.
That is more valuable than hanging on to a second QB