On all switch chips HW offload is disabled when using the Bridge Horizon feature.
Some of these switch chips support port isolation in hardware - in Switch menu, or in SwOS.
Basically for N ports there is a matrix of NxN bits to enable/disable forwarding for any possible pair of (ingress, egress) ports.
Could the Horizon feature simply be translated to clear some of these bits, and keep HW offload enabled?
Or am I missing some corner cases which make this difficult - does Horizon work in some way differently than forwarding-override in Switch menu?