Debugging and contributing to large and complex C++ projects is not trivial. I personally do debug and contribute to open source projects using technologies I’m confident with, but when it comes to Inkscape I can’t do much more than to do nothing and to hope for the best.

Filing reproducible issues is probably a good start and anybody can do it

Yeap! As a developer, having a well described bug, with clear steps and conditions, is sometimes 90% of the work needed to fix it.

Not sure about how the story with Inkscape looks, but it can be difficult to deliver the reproducible issue. You might have to build it yourself, might have to install a compiler in the right version and so on. Depending on the build story of Inkscape, this can take days of fumbling. Not many users are willing to go through that.

I would say it is OK to open an issue, which is not 100% reproducible, as long as it has not been opened. It allows for the chance, that others can try to find that reproducible way of causing the issue, who are more knowledgable about the software and might have the dev setup already on their machines.

A good issue report requires some knowledge and expertise though. Anyone can say it doesn’t work as expected, but it’s harder to identify and reproduce the problem and provide all the useful details.