Feature Request: Fail Image Conversion Avoid Retries

Hello,

I love your plugin. After doing a special configuration its fulfill several client sites needs.

I use a lot the feature “bulk conversion”, but there are several files that due size or other tech issues are not able to be converted. Anyway, each time that I click “bulk convert” it tries to convert such files again and again, till it reach new files (the ones that I am interested on convert).

So, my request is simple, if is possible create for example a “file.xxx.fail”, so the WebP does not try infinite times to convert such files.
[I don’t know how works the convert on request, but if is the case, also apply such feature there too]

Regards,
Aniscartujo