I don’t have an Xbox anymore, and I’m not aware of any way to import flight plans or weather presets from outside of Xbox. There may be one, I’m just not aware. EDIT: Looks like you can, but only if you have a pc too? lol. Load Simbrief Flight Plan on Xbox - #17 by Topher420247
That said, you don’t really need to use any specific weather preset to glide in ridge lift. You can just select any weather preset, and then set your ground wind speed to 6 knots, and set the wind coming from 90 degrees to your direction of flight. In other words, if soaring along an east or west ridge you set the ground wind to blow out of the north or south at 6 knots. If soaring north or south along a ridge, set the wind to blow out of the east or west. Then just soar along the downwind slope, because the ground wind will rise up that slope and give you tons of lift. Enough to pass 150mph in a DG-808, maybe 170.
Now, certain clouds types in MSFS DO currently produce thermal activity, Thermals, Up & Downdrafts - Realism Update/ Airmass Simulation - #422 by ANRI8496
All in all, soaring in MSFS is a serene experience. But it’s not just peaceful, it’s challenging. You’re constantly making decisions in a way that you don’t have to in powered flight.