Euro Truck Simulator 2 Input Delay Issue After Integrating External Map Modules (Qt 6.6)

[meme001]

Hi everyone,

I'm currently experimenting with a Qt-based launcher project for handling modded game profiles, and I’ve run into an odd issue while testing with Euro Truck Simulator 2.

The problem: after integrating custom map modules through a profile manager built in Qt 6.6, the game occasionally experiences noticeable input lag — especially on steering events. No changes are made to the core binaries; the launcher only configures .sii profiles and injects paths via external config files.

Here’s what I’ve tried so far:

• Verified that the delay doesn’t occur in a clean vanilla setup.
• Ensured no background threads in the Qt app are blocking the game process.
• Used QProcess to launch the game with reduced I/O priority.
• Tested both Windows 10 and 11 with the same result.

A few folks on GitHub suggested this might be related to the way modded profiles are being parsed or how the game initializes mods after load. It could also be related to how the Qt app interacts with the filesystem or cached paths. 🤔

For context, here's one of the module setups I used for testing:
This is a basic map extension with no script-level changes — added just to reproduce the delay in a controlled way. I'm using it purely for testing purposes, but it’s publicly accessible in case anyone here wants to try and confirm the behavior.

Has anyone here ever encountered something similar — with Qt tools affecting game timing or mod loading behavior? Any ideas on how to isolate whether the problem is in Qt's handling or the mod structure?

Thanks in advance for any thoughts or similar experiences!

— First-time poster here 🙌