I was wondering what happens if you have the same mac addresses on different vlans.
If mikrotik uses an arp table for each vlan it should all word fine but does it do that?
The same mac on different VLAN is never a problem, you will have different IP addresses with the same MAC
all in one table.
It would only be a problem when you have the same IP on different VLANs each with a different MAC.
This would be the case when you have VRF and overlapping networks.
I know Linux can optionally handle this, so probably MikroTIk sets this option correctly when using VRF.