I have no the 3 units setup in my 2 floors hows and it provides pretty good coverage, but...

I wanna add additional units, one per every chamber so there will be no quality-drops at all plus every room will be wired connection => max speed.

So far the connection is as following, all in access point mode:

• Main unit, wired to the ISP router
• Middle floor unit - wirelessly connected to the main one
• Second floor unit wired connected to the main one (to the second port)

The changes I am planning:

• to wire the middle floor unit. Question: what would be the recommended connection here
  • wire to the second floor's unit?
  • put a switch on the main unit second port and have the middle unit and second floor unit connected to the main one through the switch?
• if I add 2-3 additional units to rest of the rooms:
  • should I wire them in kinda sequential mode so it will create like a line of units OR
  • is better to have all the units connected to a switch that will be connected to main unit second port? OR
  • it doesn't matter what unit feeds whom, as long as they are wired to the second port of each other?