@ireneista @mhoye exactly, i've copy pasted a link and truncated it or something so many times while making another blog page or sending an email etc.
URLs get truncated in emails by 80 column format limits all the time too.
If you ban on a single 404, or repeated hits to a single truncated/corrupted URL, you'll cut off a lot of legitimate users. Specific bogus URLs, e.g. .asp and .php URLs when your site is written in python, make a lot more sense as poison ban URLs.
As someone who is currently unable to order delivery from my local grocery store due to excessively paranoid WAFs, I'm strongly against this kind of hair trigger defense mechanism.
I've stopped buying components from Mouser because they lock me out constantly for reasons unknown, doing a single search for a component part number is often enough to trigger it.