Also, I don't use Resilio's proxy servers either, so all of this is 100% running on my own infra. I have Wireguard setup on my home network, so if I am away from home, I can "VPN" in on my phone and then open the Resilio Sync app to sync up remotely.
(1) Setup Resilio sync on my NAS
(2) Shared the folder holding the kdb file via Resilio Sync
(3) Entered the code into the Resilio Sync mobile app
(4) Performed an initial sync of the folder to my phone
(5) Downloaded Strongbox and pointed it to the kdb file under the "Sync" location in Files on iOS(I miss Windows Phone here in that I could directly share my Resilio file and its sync status with a KDBX app as Resilio was a standard file host. iOS really should standardize something like that instead of forcing a unidirectional Share as the only pattern.)
(ETA: I tried Files which is supposed to do something closer, but it didn't seem to work for me.)
I gave this up though as Resilio will detect conflicts and prevent overwriting in case that did happen and I make automated nightly backups of my password file, so I can restore the file if I ever did "lose" a password. I've been running with my current setup and haven't had to restore yet.