I would like to ask if you know what ports is Dev A, Dev B, Dev C and Dev D is running. If you are able to specify different ports on the said device you can do port-forward rules in RUT955 to reach the Dev A-D.
If you are using 192.168.192.X/24 in the zero tier network and Dev A-D is running services on port 80.
Also an example addressing of zerotier will be like this:
192.168.192.10 -> RUT955
192.168.192.51 -> PC A
192.168.192.72 -> PC B
If you make Port-Forwarding rule on RUT955 like this:
External Port -> 90
Internal Port -> 80
Lan IP Address of Dev A (Assigned by RUT955): 192.168.1.110
Source Zone: Zerotier
Destination Zone: LAN
If you enter this address to the browser: http://192.168.192.10:90 -> this will redirect you to the Web Interface of Dev A.
External ports must be different for each Dev A-D devices.
You can assign them example: Dev A (90), Dev B (91), Dev C (92) and Dev D (93)
For more information you can refer to this link: https://wiki.teltonika-networks.com/view/RUT955_Firewall#Port_Forwarding
Hope it helps