Good work and progress (as always!)
I would bet that you will have no problems with either Legacy or DCS. But testing as you are doing, as you progress, is the best way to take care of any problems if they were to arise.
My train room is 33-ft x 38-ft, and has a stairwell within, as shown below. My Legacy base is against one of the 38-ft walls, one DCS TIU is under the layout, and the other in a corner. I never have problems with the DCS remotes accessing the TIU's, or with the Legacy remote communicating with its base.
Essentially, I can control both Legacy and DCS from anywhere I want, other than the Legacy remote is 'blinded' if I stand behind the stairwell, which is not necessary.
I quit placing the Legacy remote on the base for charging over a year ago, and instead use Lithium batteries on that remote. The set of batteries on that remote today is the very same ne I put on over a year ago. Therefore, I don't have to have ready access to the base.
I have another base - charge only for my second Legacy remote, that one I is still use as intended, and it is out of the way, just for charging.
Good luck, thank you for sharing, and keep us posted.
Note locations of the the two DCS TIU's, five AIU's, and of the main Legacy base.
(Click on picture for better details)