If I perform an SSDP m-search lookup (https://github.com/codingjoe/ssdp/blob/main/examples/request_msearch.py) on my laptop that is plugged into a pepwave (surf-soho/max br1), do I need to modify/ensure any configurations for it to find WiFi connected devices to this same pepwave (in same network).
Ssdp searches will only be responded to by devices that support that protocol. Not all wireless devices do. Mostly I have seen TVs, Gateways, and other various IOT devices implement this protocol, but not Wi-Fi adapters.
if you want to see all the wireless clients attached to the router - look at the client list through the web UI. Forgive me if the soho or max br1 don’t have this page - I assume that it does. I have neither of those devices to confirm.
if you are asking about generic network discovery stuff and whether the router allows that traffic by default - that is another question entirely. Do you have VLans implemented? If not, my guess would be that it would work - it really only needs a layer 2 broadcast domain for it to work.