I gathered and sorted as much Kizu genga as I could. I also added anime screencaps and GIFs for comparison purposes.
If you know where I can find more of those, please let me know, so that I can update the collection. I know that in 2017 Taiki Konno, one of the key animators (responsible for doing the gym storage scene), posted on his Twitter account (@konnotato) several genga, but he deleted them all, so I could just search for them through the internet. I wonder if there's something good missing.

PS: I couldn't find the corresponding scene timestamp for some, so in case you know, please tell me and I'll update it.
PS2: Torrent has higher quality GIFs and also videos

01: Cover (alternative version of #43)
02-66: Hanekawa
67-111: Kiss-Shot
112-119: Koyomi
120-123: Meme
124-131: Vampire Hunters
132-154: Misc + Storyboard (not key animation technically, but I thought it's worthy including them anyway)

You're a man of god

Base +5, NanaMatoi +7, Lily Starless +5, ChipmunkYe +3, Zzm 1247 +2

thanks a lot!
where'd you search/find these, and can you gather the ones for Nisemonogatari as well? im really curious on what we got for the shinobu bath scene

Base +8, Lily Starless +5

@xerxBreak Google, Twitter, Reddit and 4chan (and Yuki.la, that I think doesn't exist anymore) were the main sources. But I don't think I'll do the same for Nise, both by lack of interest, time and patience; and the likely lack of available content. Kizu is a more recent, bigger and more notorious thing than Nise was, and even for it there were little material, and most of these Kizu genga were posted unofficially by an animator on his Twitter, and deleted right after.

Base +3

thats a shame, but oh well
c'est la vie

Base +8

Thank you for these, what a great collection. Also thx for the torrent! :)

Base +5

Ah, you are men of culture! I love the *monogatari series, especially Kizumonogatari, so thank you. This jewels should be saved for centuries!

Base +7