Just looking at this on the first page from when I reported this
UE50MU6120KXXU | Lx3: Y* | SNES: Y | Lx4/5: Y*/Y | Steo *Lx3 needs tweak for 50Hz source, Lx4 does not work with 50Hz.
Just in case anyone does have a TV similar to this one, this in theory should get you Lx4 in PAL as 1080p 50Hz https://videogameperfection.com/forums/topic/expand-vertical-active-area/#post-23848
For the Panasonic EX700, I should also mention that SNES Lx2 only works in 50Hz (forced 16:9), but not Lx2 60Hz. The image just keeps losing sync in Lx2 at 60Hz (only for SNES 60Hz). However, SNES works fine in Lx3 at 60Hz using that same tweak from marqs for 1366×768.
Also, even though it’s an older set, the Samsung UE22D5003BW works the same as the above Samsung set I reported. It works with all modes in 60Hz. Passthrough, Lx2, Lx3, Lx4 and Lx5. At 50Hz you can get Passthrough, Lx2 and Lx5, but with the use of tweaks you can get Lx3 in 720p50 and Lx4 in 1080p50.