When the game start to entering midgame, it become "challenging". I have to try different settings and found some tweaks that works on my laptop. So this guide may helpful for you.

I have RTX3050 with 4GB VRAM, 16GB RAM. My goal is at least achieve stable playable state (25-40fps) with acceptable look. If you think you are in the same boat, follow this guide, it's worth to try.

Tag
⬆️: Game changer, high performance boost.
🕛: Performance first approach. Try higher if if you think your machine capable enough.
🖼️: Need for visual (in my "acceptable" term). May reduce performance but i prefer to keep it.
🤷‍♂️: Idk, sometimes impact, sometimes not. Try different settings.

Display Setting
⬆️ DLSS: On (Quality/Balanced, below that will looks ugly)
🤷‍♂️ Vsync: try different setting (now i prefer it off)

Graphic Setting
🕛 Texture: Low
🕛 Shadow: Low (off is ugly, this is lowest i can accept)
🖼️ Soft Shadow: On
🕛 LOD Setting: 15
🕛 Effect Distance: 15

⬆️ Low Latency Mode: Ultra
⬆️ Power Management Mode: Prefer Maximum Performance
⬆️ Texture-filtering Quality: High Performance

Find Config.xml file in "Document\Egosoft\X4\<your_id>". Open it using text editor like notepad.
Edit:
🕛 <chardensity>0.30</chardensity> (below this npc seems not spawn in station)
🕛 <trafficdensity>0.00001</trafficdensity>
🕛 <stardustintensity>0.00</stardustintensity> (i don't see any visual change though, but can give slighly performance)

I found that X4 not run well when I overclocking my CPU, such as using Turbo mode (in Asus) the frame rate become unstable in any settings. So I keep usinh Performance mode instead.

- Previously high frame drop when entering busy sector or wharf. Now it's still, but soon it become more stable it self.
- Previously high frame drop when open map nor view Channel Live Stream. Now it's still but less drop and soon become stable, less frustrating.
- Previously huge frame drop when entering build mode. Now I can build with stable fps, WOW.
- Previously the game crash when i use steam auto recording, so I turn off for X4. Now i can use it, YES.
- Most of the frame drop previously have low chance to fix via saving the game or Alt+Tab, now it has higher chance to fix.

Let me know if this work for you.
Or do you have any better solutions?