I extracted the jpg thumbnails (they were a bit larger than thumbnails tho) from the Komiflow website then upscaled them in waifu2x. I tried using bigjpg to attempt to get them to a higher resolution but they were pretty blurry so I didn't use them. I might try making replacements which are upscale and sharpened if this is too lowres if anyone is interested.
Please support the artist if you enjoy their work!
Link to the Komiflow page (needs VPN to access): https://komiflo.com/#!/magazines/weekly-kairakuten