I personally wouldn't spend much more time on building up the mesh for this issue as it won't solve it, been down this road for a while now.
At least for Schlage locks the solution seems to be from another post from @craigspree Adding Aeotec Range Extenders has made my BE469 and FE599 locks reliable which is to add a separate hub ($74.95) next to each lock. Can verify this has also worked for me
If you don't have lan cable access you can also add one of these https://www.amazon.com/gp/product/B018YPWORE/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 $44.53
And while your at it don't risk database corruption from power outages so add one of these also https://www.amazon.com/gp/product/B004OR0V2C/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 $39.95
Tie them together with the HubConnect App
So you can fix the lock problem (at least Schlage) on this platform for an additional $159.43 (per lock)
In your case with 6, I would just put them on a different platform.
