I took the plunge to move to -current about 2 years ago, but after a botched update I've been on a linux hiatus until now. I was able to restore my system via an image that was made prior to the update, however it was already updated to -current. I realize now that 15 RC1 has been released, things should be more stable now and I've already updated slackpkg, slackpkg+, and multilib, but nothing else. with every slackware release there's an upgrade text that eases the upgrade process by stating some gotchas and additions that need to be addressed after the upgrade before the system is fully functional. is there such a text now that I can use to move to 15 RC1 aside from combing through the massive -current Changelog?
part of the reason for the botched update mentioned was that it became somewhat of a daunting task to follow the -current Changelog so I went ahead with the update blind. is there a better way of following the changes to -current going forward?

This "howto" might be what you're looking for:
http://docs.slackware.com/howtos:sla...:systemupgrade

One might discuss whether there actually has been a slackware 15-RC1 "release". On Aug. 16, Pat wrote in the changelog that "...here is Slackware 15.0 release candidate one. Consider most things frozen and the focus now to be any remaining blocker bugs." But since then it has been "business as usual" in the -current repo with upgrades more or less daily.

Considering all the changes in -current during the last two years, a better (maybe even faster) alternative to upgrading might be a fresh install. Thanks to AlienBob you can grab a fresh ISO here:
https://slackware.nl/slackware/slackware64-current-iso/

Or, since you obviously want a multilib system, a convenient alternative might be one of his Liveslak isos (less than a month old):
https://download.liveslak.org