[OpenWrt Wiki] Supported devices
https://openwrt.org/supported_devices06.04.2021 · SoC / target supported by OpenWrt. Sufficient Flash to accommodate OpenWrt firmware image. 4MB min (won't be able to install GUI (LuCI)) 8MB better (will fit GUI and some other applications) Sufficient RAM for stable operation. 32MB min, 64MB better. DO NOT BUY DEVICES WITH 4MB FLASH / 32MB RAM if you intend to flash an up-to-date and secure ...
[OpenWrt Wiki] VLAN
https://openwrt.org/docs/guide-user/network/vlan/switch_configuration05.11.2021 · Newer devices with embedded switches (like Netgear R7800) use the DSA switch driver, that creates a distinct network interface for each switch port as if they didn't have a switch at all. Most OpenWrt-supported devices can use the DSA driver, but they aren't ported over yet because the switch configuration would change significantly and likely break any custom setup …