Not sure why you inserted "Open" - I surmise to imply support the 3rd-party firmware?
From the developer's page at: https://divested.dev/unofficial-openwrt-builds/mvebu-linksys/#goodies
Divested-WRT: No-nonsense hardened builds for Linksys WRT series
They link that as the forum thread.
DSA devices don't come with VLANs enabled by default. Do you require VLAN tagging to a remote device?