Tvheadend

Hi there.

This post is a bit of a sanity check as this whole thing is kind of frying my brain, but I'm hoping someone here might have the know how to figure out this (somewhat) simple task.

My goal is to link two TVheadend servers together, say one with Freeview DVB-T2 and one with DVB-S2 elsewhere in the world, by importing the DVB-S2's channels into the DVB-T2 box through a .m3u.
In theory, this would then give the DVB-T2 box all of DVB-S2's channels through IP without any transcoding, acting as if they're just regular channels with EPG and whatnot.

I know it's possible to import .m3u through "DVB Inputs -> Networks - > IPTV Automatic Network", which should give the desired result (all channels, one server). I'm wondering if this is the best and only way to achieve what I'm trying to do, by just sending the offsite box's .ts through URL. Right now, this isn't working. My .m3u looks like this

#EXTINF:-1 tvg-id="ID" tvg-chno="1",NPO 1 HD
http://usr:pass@ip/stream/channelid/id?profile=pass

and so on for the other channels. TVheadend doesn't detect any services, so I'm wondering if my process or setup of the .m3u is wrong? the .m3u is just the "playlist" output from the other server. Does anything need to be modified for the DVB-T2 box to pick up the DVB-S2's playlist .m3u?

EPG is another concern. Would something like WebGrab++ have to be used as a method for getting the EPG? Could I somehow get the EPG from the other server? etc, etc. Any solutions for EPG is also welcome.

Finally, is there another simpler / better / more secure, etc way of going about this? Be interested if I could see other setups or guides for a similar thing.

I'm sorry if this has been asked before/often. Obviously new here so please point me in the right direction if at all possible.

Thank you!