Cmp The latest updates (in the 6.12.x range) add ACS (automatic channel selection) to bridged eero networks.  Previously ACS only worked on eero that were doing the routing.

The eero can use DFS channels if they are available but there are times when it will not.  Most DFS channels require lesser transmit power than non-DFS channels, so there are times where it makes sense to use a more crowded non-DFS channel to get higher throughput than a DFS channel with lesser transmit power.

Cmp Prior to v6.12.0 only non-bridged eero had ACS

After v.6.12.0 non-bridged and bridged eero have ACS

Cmp It won't make a difference to a non-bridged eero network, the non-bridged eero already had that capability.

Cmp I do not understand your question.  eero's ACS can select DFS wireless channels to use if they are clear and it makes sense to use them.  There are circumstances were a DFS channel might be clear but would result in slower speeds, since they limit transmission power on those channels.  In those cases the eero likely will pick a non-DFS channel to use.

Cmp DFS might pick a different channel so you are on a different channel than your neighbor. It might not. It depends on your environment. We cannot force it to pick a specific channel. I hope this answers your question.