Reverse split question

During a reverse split, how does it work in regards to fractionals and whole shares that aren't to a count of ten? Asking for the possible 1:10 APE/AMC RS.

Example Position:

136.14 AMC

76.33 APE

Becomes:

212.47 AMC

then 21.247 AMC post-RS

Or would they give cash in lieu for 2.47 shares and then RS goes to 21 shares? It seems like regardless of the split ratio, the brokerage (if they offer fractionals) could maintain your position 100% in the stock without paying cash for liquidating, and simply divide down to a new fractional position. It also seems like you don't need to have a share count divisible by 10 after the conversion, but I don't know what the rule is there.

I haven't seen anything about this question anywhere and would love to know what to expect, if it happens.