https://kanin.cannot.date/2022/12/31/g0so.mp4

rtp:
  world: world_spawn
  triggerblock: NETHER_PORTAL
  pos1:
    X: -60
    Y: 46
    Z: 23
  pos2:
    X: -72
    Y: 22
    Z: 23
  portalArgs:
    command:
      '1': dm open all

Its a vanilla thing, GUI's are closed automatically when you are in a portal block.

Youll need to do a water portal, air portal or something other than nether portals sadly :(

Ahh that makes sense, thank you!