I'm not exactly sure how the TP-Link handles this. But I would say form a basic network understanding you will need to create policy based Bandwidth control routing for the LAN side of the WAN IP it...

OK, So if I move up to that type of cost for that L2 switch with those features would it be more beneficial to use the L3 switch around the same price range?

Welcome. I hope that is what you're looking for.

Advanced>Load Balance>Policy RoutingSource would be your LAN ip range, destination 0.0.0.0 (any) and select the desired WAN port (s). Create additional rules as needed.

Model : Hardware Version : Firmware Version : ISP : OK, I have screwed myself sideways here. I first ordered an ER6120 and (2) TL-SG1024, due to having 2 ISP and 1 of those giving me 2 Static IPv4...

Just because I hate when people post and never update.... I simply deleted the config and rebuilt all rules with the wan reconfig. And all is well. All gaming via the Netduma/DMZ are happy.