Anywhere you like, if at all.
Ricoh MFPs can lock up if you look at them funny, let alone send them a specially crafted postscript file. If you've found yet another way of making them crash perhaps post about it on your favourite comment site/write it up on your blog but it's probably not going to get Ricoh or their customers particularly bothered (as you've found) and probably won't get assigned a CVE.
There don't currently appear to be any CVEs raised where the only risk is of a device crashing for instance:
I run around a dozen Ricoh MFPs which the whole of my network can send postscript files to directly and yet this discovery has elicited no reaction from any of my team. If they did patch it most printers wouldn't get the fix for years by the time they had analysed the issue, made a new firmware, affected devices had been replaced or undergone maintenance resulting in the latest firmware being applied. This isn't the sort of issue that would call for a critical advisory and immediate application of patch sadly, if you're in a position to send print jobs directly to the printer you're in a position to DoS it (not to mention additionally wasting materials/creating sub2pewdiepie pages) by sending it print jobs?
Also worth considering: If they aren't going to fix it and any fixes they do make won't make it to the vast majority of affected devices, perhaps the most responsible thing is to not disclose the specific details of vulnerability at all?
And to the person that said mentioning that it's a Ricoh device crashing, that it's annoying to fix once it does, that it involves sending a postscript file to it, is so specific as to be almost disclosing the fault itself? The information contained in the original text is about as dangerous as a locksmith revealing that you can jam a certain brand of lock by directly inserting a malformed key. It's both highly generic and highly predictable as far as I can imagine?