V1910-48G switch, under 5-20-R1518P01, how do port isolation and VLANS interact??

[n3mmr]

I'm confused by the user guide for the V1910 R1513 software, when trying to set up Port Isolation and Vlans at the same time.

Suppose one has three extra VLANS, 2, 3 and 4

Suppose port 11-20 are only in VLAN 2 and that ports 21-30 are only in VLAN 3. All other ports are only in VLAN 1, the default VLAN.

Suppose also that ports 11-30 are all in the port isolation group.

1. Are ports 11 and 12 isolated from each other? I suppose "yes". Right??

2. Are ports 13 and 23 isolated from each other? The manual is unclear in this. One port is in VLAN2, one is in VLAN3, and the manual talks about ports in different VLANS always being able to communicate.

Are ports 1 and 13 isolated from one another? Also unclear. For the same reason as 2.

Would things change if the VLANS were tagged? Does having trunk or hybrid or access port types make a difference??

[16again]

If ports are in different VLANs,  they're already isolated.  Unless you're routing between VLANs.  When routing, apply ACLs

Isolated ports are for use in a single VLAN.  They make sure clients1,2,3....N  can't reach each other, but they all can use they uplink port to access the ......(server , internet router, core network.. fill in the blanks)

[n3mmr]

Be that as it may, it does not answer my questions, not at all.

I am fully aware what large switch systems will allow you to use vlans for, but in the V1910 we're limited to 256 vlans.
Also, we do need to use vlans for special purposes, two mgmt vlans for two very different networks, an ip phone vlan to route those few people thru a different main router and then we need isolation for about a thousand tenants.
So I still want to know how vlans and port isolation interact, the v1910 manual seems to say ports that are both in the isolation group and in a vlan can communicate with each other.