Balancing two different network over Wlan or lan

[AashishAS]

This is my current network topology.

I would like to make the bandwidth on my 1st Connection (Fibre) available on my OpenWrt router that dials a 2nd connection (PPPoE via Eth) and the connected Dumb wifi6 Ap.
Both are same ISP and same plans, but different public ipv4/v6.
I know that to achieve double bandwidth is not possible but would like to know about load balancing and weather it would work for 2 clients connected to my Wifi6 AP ; I.e; if 2 clients connected to my wifi6 AP be able to get 120Mbps each simultaneously?

Thanks!

[frollic]

This is pretty much the same question

MWAN3 doesn't seem to increase bandwidth - much

Just got a second ISP (moving from one to another) and thought I would do some dual-wan testing to see if I should consider keeping both. I configured both WAN interfaces and individually tested each. They have similar bandwidth, both in UL and DL speeds. Then I used MWAN3 to load balance the interfaces and did some further tests using a multi-connection download client. What I found surprised me. I can see each WAN port is handling about half the load. However, the additional bandwidth gained…

[AashishAS]

Yes I see it didn't work well for op.
I wanted to ask if I can connect the 2 routers using 5ghz wifi, is it possible to merge both wan then?

Edit: Got the setup to work and am getting pretty much twice speed on Speedtest.
But when trying to use upnp(libretorrent) it loads the CPU upto values >2 and system stutters. Anything I can do about this? Also the Active Connections bar rapidly fills to 99%.
Any help would be appreciated.