Knowing in advance which kind of layers won't be converted successfully sounds reasonable to me.

As the matter of fact, when you enter the website: https://avocode.com/convert-psd-to-sketch/ - there is a call to action to "Read more about supported features". If you click it, you would see a page explaining what will and what won't be converted. Here's the link: https://avocode.com/convert-psd-to-sketch/features

Why don't you calm down a bit before getting all jumpy?

There are lots of details that could be helpful. What kind of limitations are there? What does it convert? Is anything discarded in the conversion process? What does it do with items where there isn't a 1:1 conversion? What does it do to features that aren't available in Sketch? You know... the things that are included in the description that OP provided in response to my comment and that he updated the main thread with... There is a lot of technical info that would be helpful. I didn't have a .PSD file handy to test so I was asking to try and be informative and helpful.

Here's a list of currently supported features: https://avocode.com/convert-psd-to-sketch/features along with additional information about features that are in development. Since it is a "PSD" to Sketch Converter - the best way to try is really just by trying to convert a PSD design and opening in it in Sketch afterward.