@quasaur So you mean having a single supernet broadcast domain with e.g /22 mask and have many / 24 "subnets" with a /22 mask and single gateway?
If yes, it can be done, BUT the issue would be tha you need to manage all mac addresses manually.
It can be done but it is very cumbersome, especially in the long run.
You are better off segmenting your lans with vlans and use single dhcp on pf to manage them all.
You cant have rules between them as long as they are on the same physical interface too