How to set up PRO 900 HP modules to form network with routers and sleeping sensors?

Newbie here, please bear with me.

I want to form a network of a PC-connected module talking through several always-on middleman modules (thus acting as range extenders) to distant endpoint modules which will be on asynchronous cyclic sleep with pin wake-up(SM=5). The “Base Unit” connected to the PC will be in API mode so that I can talk to it using C# code.

I need the modules to wake up approximately every 4 minutes so that I can monitor them. Ideally, I would get them to return battery voltage. After that, they should go back to sleep to conserve power.

I have connected my digital I/O contacts so that sleep request is de-asserted when the sensor reading is to be taken on another digital I/O line. If I read the various docs and forum posts correctly, that is problematic, and I need to do I/O sampling so that a reading will be sent on wakeup. Is that correct?

I will also set an output on these modules every so often (a heartbeat) and also set the output when the digital I/O is actuated.

I have been successful at using one module as an indirect polling coordinator, with TO = 0x40. and the sensor as an Indirect Message Poller. Some of the docs I’m reading say that this is Point-to-Multipoint, and it only works in a star configuration. Other docs show a mesh-like configuration. Which is right? Is there no routing in P2MP?

Should I be using Digimesh instead of P2MP for this?

This is probably something that would be best being emailed to Digi Sales or Support instead of posting here on the forum.