By Tremote Connection I simply mean choosing the library to use from Playing From under Playing Now - the bottom part of Playing Now.
Some history. Tremote is just the predecessor to what is usually called Client-Server today. It stands for Terminal Remote and was introduced when Netbooks were introduced as a way to use a server library on a small client, so that you do not have to maintain the library on multiple systems, especially small systems like Netbooks. It downloads a temporary version of the service library onto the client and also allows you to play either on the client or the server. Over time, some options other than playback were added, like the ability to edit tags on the client. You do not have to use Tremote to be able to see and use DLNA renderers.
Some people, like you, have trouble seeing networked systems using DLNA under Playing Now. This is normally a problem with Firewall settings but can be somewhat hard to find. In the past, some WiFI modems even had internal limitations that stopped MC from discovering other systems, although I think that is rare today.
My conjecture was that using Tremote may help in some cases where MC was not discovering other systems. Zipa's observation seem to indicate it helped him, but I have not really investigated it in detail.
When DLNA renderers do not appear in Playing Now, setting up Windows Firewall to allow a problem through is the first thing to check. You need to do that for each major version of MC and on each system. If you have a hardware firewall, you should check that also. Sometimes the firewall settings solve the problem, sometimes it does not.
I cannot play from W10 to my W7 system, even though I can load the W7 library onto the W10 systems using Playing From (TRemote), but I never need to force output to that system, so have not pursued it beyond the obvious firewall checks. The W7 renderers do not appear on W10 Playing Now.
At one pont, I have problems between W10 Pro and W10 Home, but I have not seen that recently.
Hope some of that helps.