Your feature request has been answered! The site now checks if '.com' and '.io' are responsive. I just found amaztion.com, bokic.com, prosable.io from this. I'm stoked.
Just click the name to start checking.
Please note however, the check is not "100% accurate" if the name has been registered, it just checks if the site responds, which heuristically seems a pretty good approximation. I.e, all the ones it said were ok, I checked on name.com and they were all unregistered.
I hope you get a better go next time! I just got 'amaztion.com', and 'prosable.io' I was stoked.
I thought about filtering the words to make them more 'readable' but I decided that, for me at least, seeing all that unfamiliar randomness, helped me riff on what names might work. Like, "Oh, that sounds alright, if I just move that letter around." So I think the random words can work as starting points, as well as the words that just work: like 'bookism' (the .io is there).
It just performs some random modifications of the words you enter: delete vowels, double letters, and add a suffix as well as a bit more. There name checking doesn't use whois it checks if the site is responsive, which seems to be reasonably (tho I wouldn't claim 100%) accurate!