I ordered a similar device ONti a while ago, looks identical, got it on some black friday or singles day from ali.
Onti 10Gb 8port sfp+
This device gets warm, no doubt about it, especially when using 10GBASE-T SFP+ tranceivers. I added a small heatsink on the rj45 tranceiver and a 'custom' cooling fan in a 19" rack. like this one
2u 19" cooler keeps the temps somewhat under control.
when using with dac or fiber tranceivers, it should be fine.
For what I'm using it for, seems to work fine. Yet another webui to get used to, not too different, but something else then Zyxel, Mikrotik and opnsense devices.
I have it connected to a Mikrotik CRS309-1G-8S+ and they get along allright. the reason i purchased it was to connect these 2 10gb switches where I have a CAT7 ethernet cable that cannot be removed without breaking walls and floors, so i went with the 10gbase-t tranceivers.
I do get 9.7-9.8gbits/s in iperf tests