Has anyone run OpenWrt a mini-PC such as (HUNSN RJ42) or similar device?

Ubiquity switches with Etherlighting like Pro Max 16 PoE are indeed not the cheapest but look very cool ! => see Switch with Etherlighting

When reconsidering that you need something more budget like you could check into Netgear GS308EP => see Basic VLAN setup for router / managed switch / access point for some screenshots of its UI