Okay, first off, some things seem to not be working on the compatibility filter in the lists, where you go to choose a part. At least one situation this can be seen is in cases.
For example, take this parts list, which has 8x 3.5" HDDs, 4x 2.5" SSDs & 4x 5.25" blu-ray writers.
Going to the case selection screen still shows cases with 0x 5.25" bays and 1x 3.5" bays.
Trying the same thing with motherboards is also not working properly, either - it's showing mini ITX boards as being compatible, none of which have the 16 SATA ports required for that list.
My main browser is Chrome, but I also tested this in Edge (to see if my adblock / ghostery plugins were messing things up) and it also failed there.
I think several months ago, the motherboard compatibility checker was working properly, but I think the case one has been broken for quite some time before that. (It may have functioned when I parted out my current system in late 2014 to January 2015, but I'm not sure. Btw I'm not looking at getting that many drives, at least not now, I was just using that list to show how the compatibility checker is broken.)
Also, speaking of case compatibility, would it be possible to check for compatibility issues, where the 5.25" bays and 3.5" bays are shared, like they are in some cases? (For example, some cases advertise maybe 10 external bays and 8 internal bays, but they are shared.)
And what happened to being able to see case dimensions or sort by them, on the case selection list?
Also, when I go to filter vendors, show prices, etc, when I'm logged in, I want to be able to require that shipping costs be included. I currently have vendors that don't always show shipping costs unchecked from my preferred vendors list, with the exception of Amazon.
I feel I'm forgetting a few other things. As I come across them, I'll either reply or make a new topic, or if possible, edit this post maybe.
Just remembered another thing... I'd really like to be able to work on multiple part lists simultaneously. My current workaround is using a multilogin plugin for Chrome that I've had quite a while. (It's no longer available; also a deficiency it has is forgetting my extra site sessions when restarting the browser, or when closing and ctrl+shift+t re-opening tabs.) But, it'd be nice to be able to do it natively.
Also, for the price trends at the bottom of each part page, I'd like to be able to have it reflect tax & shipping, but not include mail-in rebates. And, I'd like to still see price graphs for somewhat older discontinued parts, provided that the dropdown will go back that far. Currently it goes back 2 years, it'd be nice to have the option of making it go back farther (I'm thinking to when pcpp was founded), and optionally show a horizontal scroll/zoom bar based on user preference.