I know what you mean about the lack of info on some filters. Here's some of the stuff I've discovered. I have an '89 Electra Glide. The Purolator M/C specific filter is a ML16822.
http://www.purolatorautofilters.net/resources/Popup/Pages/PartDetailPopup.aspx?partnum=Ml16822
I have used a a Purolator Classic L10241 with great results.
http://www.purolatorautofilters.net/resources/Popup/Pages/PartDetailPopup.aspx?partnum=L10241
You'll notice all the listed specs are the same, i.e.: relief valve setting, height, thread size, etc.
Now let's look at Fram. Fram lists the PH6022 as the M/C specific filter for my bike.
http://www.framcatalog.com/PartDetailWindow.aspx?b=F&pn=PH6022
Notice however, the PH3614, has the same specs: relief valve setting, threads, diameter, etc.
http://www.framcatalog.com/PartDetail.aspx?b=F&pn=PH3614
At a glance, they both list STP S3614 as a suitable substitute. There may be others, but I didn't examine the whole list. Also, in the case of Fram, the last 4 numbers stay the same, it's the first two letters that change. PH3614, TG3614, & XG3614 will all fit the same application. However, the filtration level will changes with different letter prefixes. I've had an e-mail exchange with Jay Buckley (aka Motorking). He is a Fram rep on this site. It is on his recommendation that I am running a Fram Ultra XG3614 on my Harley. Here's Jay's LinkedIn profile.
https://www.linkedin.com/pub/jay-buckley/8/a1/903
He also does some of the Fram videos on YouTube.
http://youtu.be/JSC9KZGDRDk
If you've every seen any of Jay's posts, he always seems like a straight shooter.
Mobil 1 makes a great M/C filter. It's efficiency is rated at 99.9 @ 20 microns per ISO 4548-12. They list an M1-301 as the filter they base the efficiency on. An M1-301 is an automotive filter that fits various Ford, Mazda, Toyota, and others
https://mobiloil.com/en/oil-filters/motorcycle-oil-filters
For me, the bottom line is, do you lose sleep at night thinking about your filter? If so, do your research, then find one you like and sleep well. After all, it's only an oil filter for your bike. There are plenty of more important things to lose sleep over.