Had a night to mess around with this and to be honest Im not sure I know what did it, but I got it to appear and here's what I did in case it helps someone else having the issue (in addition to it not appearing in renoise, it was also absent in Ableton Live by the way):

1) My GPO/aria player install was out of the box on a flash drive version 1.872 and installed, the aria player version matched the aria engine version 1.872, which is the latest version offered online. I dug around deeper on the makemusic site and found a version of ONLY the engine installed that was v.1.933, but the site warns users about using it seperate from the player installers and recommends using those instead (which includes both player and engine but they are version 1.872). I downloaded and installed anyway and my engine upgraded to 1.933 (64bit). The plug still wasnt showing.

2) Then for some reason, I felt the need to try and download and install the full aria player installer on the site labelled 1.872, even though its the same version as what I had out of the box..and just installed it right over the top of my current install with the engine upgrade. After this, a rescan of my vst directory with Renoise finally detected and brought the plug into my vsts lists....and my player says v.1.872 with an engine 1.933 (win 64 bit)...and so there you go..one of those two things I tried did something that worked. :) (also I was making sure to run installers and renoise "as admin" per usual)