Good evening Jens and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
I understand where you are coming from.
Both of my colleagues are right. If you venture out of the Standard Event Tickets Plus workflow, there is a chance that some functionalities might break.
We have not run specific tests for that plugin or other similar plugins such as chained products or composite products.
But I would have to side with Brook on this. Normally the product stock aspect should work since it uses native WooCommerce stock handling.
As for the attendee aspect of things, that part I am less certain about.
The only way to find out would be to run some tests on your end.
That being said, provided the nature of WooCommerce plugins, it is likely that a template customization / snippets can solve most scenarios.
Let me know how that goes.
Best regards,
Geoff B.