Which is better for 8 users doing voip , watching youtube videos, browsing and playing multiplayer online games at a time ?

Beacon interval 100/dtim interval 1

B.i. 200 / dtim 1

B.i. 50/dtim 4

B.i. 50/ dtim 2..

My tplink router is on wisp mode and is connected with zte lte modem which has max. 1500 mtu..

What about rts threshold setting in router's setting which is more than 1500 against mtu 1500 max. offered by lte modem / service provider.

How to optimize rts threshold for 8 users at a time?