Hi, it was most likely Thomago and/or Xyga, over at SHMUPS forums. ^_-
I only tried a couple of Asus monitors – my old VW246H 24″ and the new VG275 27″, both 1080p – along with the LG 27MU67, which is 4K. Scaling was pretty good on the latter, and it rendered even scanlines with every OSSC video mode (whereas both my Asus displays mess them up quite badly in Line4x and 5x) but was absolutely useless with 480i sources (due to IPS technology not dealing very well with flickering/flashing images).
Having to guess by its specs – and assuming it’s fully ‘OSSC ready’ – the MG279Q will probably work great, with a caveat. If you plan to mostly feed your monitor with 240p contents, it’s safe to bet you’re going to be pleased. But if you have a huge collection of PS2 games, or own an unmodded PAL GameCube/XBOX console (as I do), well… Get ready for some major troubles. I ended up returning the LG and happily privilege convenience over a better IQ.