I have to laugh about 'those mirrors'. We have an extremely smart Calico cat. When I'm preparing food on the island counter, from the living area, she will look up in the mirror to see what I'm preparing. I kid you not, its hilarious watching her.
On the other note, we wouldn't be putting up any heavy fixtures; either single or a whole. We just want something nicer over the island that can be used as accent lighting. TBH, the lighting inside is too white-bright. Its weird on the eyes when we just want to relax but the small back lamps and small table lamp on our buffet aren't enough. In the evenings, we'd like our living area have relaxing lights, not like those in a classroom or office. We are trying to find a medium. We do like the single-rod (not chains that swing) pendant lights like we had in our Cyclone.
Looking at our 2015 Ashland as the ceiling fascia is a plastic moulded trim which is 1 1/4 inches thick with 12 screws holding it in place.
The led light fixtures are the same depth so the ceiling trim, light fixtures and mirrors should come down as a single unit. I really doubt they would penetrate the ceiling level.
The lights fixtures have three screws holding them place. I would pop them out first ( just turn anti-clockwise to remove the lens) and disconnect all of them or try the forward one and see if that is the first one which runs to the other three.
As the light switch on ours turns only those four fixtures on/off it should be a single run with them interconnected with the others tucked behind the fascia.
As it is only plastic i would consier the weight of your dream fixture. Plus how low you want to hang it down. Lower mounting the more ability of sway. Just ensure a secure method of attaching both sides will help.
We have been living in ours for 10 months now. We never look up to look at the mirrors.
Good luck.