Actually I was so desperate about solving this issue. I even thought my laptop is not enough to deal with this sim. But with the solution I found, I realized that my worry was unfounded.
The solution is: Loseless Scaling app.
My laptop specs: AMD Ryzen 7940HS, RTX 4070, 16 GB RAM.
Like everyone have this issue, I was getting a good FPS and then it was dropping around to 10 fps. And it was stuttering like hell when I was at the airport, even it wasn’t a busy and big one. But after using Lossless Scaling, all the stutters and FPS drops are gone, worked like a charm. Now I get 60 fps average, on ultra settings.
If you wanna try this app, need to tell a couple of things. Firstly, this app only works when the game is in windowed mode (don’t worry about it, when you activate the app, the game is being switched to fullscreen mode of the app itself). And second, MSI Afterburner is not going to be able to read the FPS, but the app has its own FPS counter (you can even see before/after FPS values). And third, I highly recommend you to read manual or watch tutorial videos on Youtube about the app. These are the settings I’m using:
Hope this works for you also.