Sorry for the late reply. The next version will fix support for 1440x images on Instagram :)

Sorry for the late reply. I might be extrapolating a bit too much from your request, but are you looking for a way to automatically reverse image search the image, and find larger versions?

If so, that's actually not what this addon currently does. It doesn't replace using a reverse image search engine, but rather complements it, because image search engines will often not provide the largest version that a site will offer.

This addon works by using APIs and regex rules specific to each of the sites it supports to find the largest publicly available version of the image that the site offers. For example, let's say that a website has the following images:

example.com/image_small.jpg
example.com/image_large.jpg

If this addon had a rule for that site, it would replace image_small.jpg with image_large.jpg, based entirely on the URL of the image (replacing _small with _large).

I'm not against adding support for reverse image search engines in a future version, but I'm not sure when I'll have time to get to that. If someone else would like to contribute this in the meantime though, I would be more than happy to accept a PR! :)

Sorry for getting back so late. It'll be fixed in the next release!

Sorry for getting back so late, thank you very much for the idea! I've tracked it here: https://github.com/qsniyg/maxurl/issues/902

The link you posted (replacing xxx) works on my end, but my guess is that it's some kind of regional update or layout change of some kind that causes it to fail for you... Can you contact me through one of the links at the bottom of https://addons.mozilla.org/en-US/firefox/addon/image-max-url/ ? (Unfortunately it's not possible to have a back and forth with firefox reviews)

Hopefully we can fix this :)

Sorry, I'm not sure I understand. I've tried it on the image below the Главное tab, and it works for me. If this is not the image you're referring to, can you send a screenshot of where the image is on yandex.ru?
If this is the image you're referring to though, can you send me your settings? (Export button at the top of the options page) Hopefully that will let me reproduce your problem and find a fix :)
My contact information is listed at the bottom of the addon's page.
Edit: Sorry, I hadn't seen your edit. My email(+pgp key) is listed here: https://qsniyg.github.io/

I can't actually seem to replicate the issue, sorry! I tried under Waterfox Classic 2021.02 as you mentioned, and it appears to work fine for me. Would you mind sending your settings (through the options->export button)? Contact links are available on the extension page (use whatever you're more comfortable with). Also, could you send an example link that doesn't work for you? For me, https://pbs.twimg.com/media/DlOC3mOWsAEi1ld.jpg redirects properly to https://pbs.twimg.com/media/DlOC3mOWsAEi1ld?format=jpg&name=orig .
It could be that there's a specific combination of settings that causes it to break, it wouldn't be the first time that has happened under Waterfox (due to its older JS engine).