Im watching https://youtu.be/C81pyQaJgj8?si=htGxI0qKuCZlUvrI. I think i understand it all (including second video) yet im still unsure about part 12:00 - 13:00. He only assigned PVIDs which adds TAG info to the packet. But he claims that from now on VLANs are also set (by PVIDs) so packets will flow selectively. I thought you have set Tagged/Untagged for port to really set VLAN on the port. I mean for example without Untagging such packet wont be recognised by “generic” devices connected to such ports.

Offcourse im aware that implementations may be different and for example my Edgerouter doesnt have Tagged/Untagged options at all. But im asking here about the standard