Hello !
Thanks again for all the support and feedback, it really keeps me going !
A lot happened since (like signing with the publisher Pretty Soon!), so this update took more time to get out, but here it is !

Main changes:

• Added a dynamic performance system: The game now monitors physics load in real time and automatically adjusts physics settings to keep things running smoothly. It works in three states: Normal (60 Hz physics, full precision), Degraded (40 Hz, reduced solver iterations) and Critical (30 Hz, minimal iterations). It reacts both to sudden physics spikes and to sustained average load, with grace periods so it doesn't switch constantly. When things calm down it eases back up progressively. This makes so ducks won't be stuck in panels or even fly through in some cases in the latest version.
• Updated the project to Godot 4.6 (Had to change a bit the general render of the game, it's not a big difference but the lightings are a bit different now, I tried to make it as close as before, maybe it's a bit better now)
  
• Using D3D12 instead of Vulkan as main rendering driver
• Fixed a physics issue with the duck collision making them lags/freeze in some interaction (One of the collision shapes of the duck were too small and Jolt had issues handling it)
• Fixed gambling boxes not saving properly
• Fixed the press and the auto duck machine not loading correctly after saving
• Added flat duck luck scene
• Fixed flat duck rotation  (they were spawning in the wrong orientation)
• Tools are now disabled while objects are spawning (prevents clogging in the spawn tube)
• Changed the smoke/particle effect
• Changed the method used to wake sleeping physics bodies above the growing pit (should be more reliable and less prone to objects getting stuck)
• Cleaned up shaders (fixes a possible crash on launch and some potential graphical glitches)
• General script formatting pass across the whole codebase

The performance system is the big one here, rather than hitting a wall and freezing when there are too many objects, the game now degrades gracefully and recovers on its own. It's not a magic fix (physics is still expensive), but it should push the breaking point much further and make the experience smoother when it does get busy.
Using D3D12 should fix a lot of issues too and the fix for the ducks lagging/freezing in some cases should make the experience better.
Still a lot to do, but every bit helps. As always, feedback is super welcome !
Thanks a lot !