Hi Antonio
I try to reply e-mails/pr's within days, but unfortunately haven't been able to review yours, sorry. Cesar is busy with some personal projects and won't be able to help at the moment.
Three weeks is a reasonable time but I prefer to give plug-in maintainers at least 5 weeks of notice before asking commit rights or bumping the mailing list, as some people may take 1 month vacation :o) but in case you have some pending issues or need anything, drop me a mail off list. I try to keep my inbox empty, so I reply e-mails faster than GitHub or mailing lists (which are filtered to other folders).
However, I started with image-gallery, and will continue first with the ones that are used in BioUno, as I have a hangout with another developer about these plug-ins in the next days.
Cheers
Bruno