This has caught my eye:

https://www.amazon.com/NOVOO-Multiport-Replicator-Delivery-Ethernet/dp/B09YKY9W8G/ref=sr_1_14?keywords=USB+C+Hub+Multiport+Adapter%2C+NOVOO+8-in-1+USB-C+Hub+with+4K+60Hz+HDMI%2C+100W+Power+Delivery%2C+3*USB+3.0%2C+1Gbps+Ethernet%2C+SD%2FTF%2C+for+Dell%2FHP%2FLenovo%2FSurface%2FThinkpad%2FMacBook%2FXPS+with+Thunderbolt+3%2F4&sr=8-14

Small enough a hub and has 100W PD (and in the visual description, it says it supports PD 2.0 and 3.0).

Quick update: When I plug in a USB-C hub (I used this one: https://www.amazon.com/dp/B09YKY9W8G) into the front port and then plug devices into the hub, they all work fine from the get-go and there are no one time-disconnects (since the hub has already connected, I guess). So I think that something happens upon initialization (switching data transfer or fast charge modes or something) and it might not be fixed with a replacement board. It could either be a design flaw that could be fixed with a newer board revision or with a driver update. It would be helpful if I could get feedback from other Z790 Hero owners if they observe the same behavior with the front port.