Shows just fullsize Image with hotkeys & without pop-ups on many image-hosting sites
There are already older and supporting more hostings scripts with simular purpose, https://greasyfork.org/en/scripts/4881-adsbypasser for example, each script is unique and does its job in its own way, you are free to choose whatever you like the most.
by the way, contributors of adsbypasser script wanted to join forces (ended with them auto-importing image supports from my script to their (I don't mind)), so you might want to ask imagehost-redirect author to join them. (I'm fine with my script so far)
P.S. - if anyone would just like to contribute into scripts github adding\fixing hosts - that would be very welcomed ;-)
adsbypasser does not support an easy way to revert to the original page (like the 'R' key in your script). I use their lite version + Handy Image
Join forces with other scripts?
https://greasyfork.org/en/scripts/2641-imagehost-redirect has a similar purpose. Instead of having two different scripts with duplications, why not merge them?
As of now, looks like your script is the more comprehensive one. Imagehost redirect has about 10 or so hosts that you don't yet support:
g.e-hentai.org
imagesnake.org
img.i7m.de
imgblow.com
imgboc.com
imgdetop.com
pictures.mrstiff.com
quickmeme.com
rule34.paheal.net
uploadica.com