Mark dual wan traffic for queue tree

Hi

i configured 3 ISP and 1 LAN for use based on different usage like gaming use ISP1, browsing use ISP3, VoIP use ISP2, netflix USE ISP3.

i want to make sure i got everything ok so i read the “packetflow chains diagram” but do not truly understand
the diagram so i like to know the right way to mark packets and force packet out certain ISP.

i use mangle rules:
chain: input, in-interface pppop-isp1 action: mark connection ISP1, passthrough:yes
chain: output connection mark:ISP1, action: mark routing ISP1, passthrough:no

In the same fashiOn Fot ISP2 and ISP3

after defining all ISP use:
traffic for ISP1:
chain: prerouting, dst-address-list: ISP1-list,action: Mark routing : ISP1, passthrough:yes
traffic ISP2:
chain: prerouting, dstaddress list: ISP2-list, action> mark connection: ISP2, passthrough: yes

where i add a whitelist addres list with domains that i assign to use ISP1-list or ISP2-list or ISP3-list and works
but i wanna be sure and recaliing that input and output use in mangle is traffic TO router and my traffic is through router.

Am i doing it right ?,

Tried to understand packet flow diagram but do not understand how to read and
apply to my scenario.

Help with an basic example weith respect to marking of packets/connections for certain ISP and if my approach
to send traffic beasde on dst address list is the best way or any better and simple way …

Thank you