Routing between networks with ethernet switch rule?

Hi,

My planned setup:

+-------------------------------------------------+
|               RB2011                            |
+-------------------------------------------------+
 eth1     eth2   eth3   eth4   eth5   eth6   eth7  
  |        |      |      |      |      |      |
 WAN      pc1    pc2   server  box1   box2   box3

The intercommunication between the machines on the LAN needs to be strict regulated. Some of them are not trusted and vulnerable, and needs to be isolated from each other, with /ip firewall filter and connection tracking.

A small subset of the LAN intercommunication require wire-speed switching, regulated with /interface ethernet switch rule, based on tcp/udp port numbers (without connection tracking)

Box1-3 needs to discover each other via a network broadcast address.

RB2011 is DHCP server for all machines on the LAN.

I’m thinking about two alternatives:

Alternative A) One single LAN IP-network, bridging configured with use-ip-firewall=yes, combined with a few switch rules for the wire-speed traffic.

Alternative B) Several small IP networks for LAN, isolating each machine, except those that must share a common broadcast address. And try to use switch rules with new-dst-port to route the wire-speed traffic also between different IP networks.

What do you suggest?

Would it be possible to route packets, between different IP networks, with /interface ethernet switch rule and new-dst-port action?