What is correct in terms of DNS setup ?

Hi all ?

What would be the difference :

on dhcp-networks point all dns servers to my mikrotik and on mikrotik DNS set it to point to my linux
or point all dhcp-network to point direct to my linux

Ii the end is all the same ? which one is the correct / fastest one ?

Is there a need to create a firewall rule to both off these options ?

I have a Hotspot in on off the dhcp servers, do I need to setup somethinkg special in order to the DNS works perfect ?

cheers