FWIW, for the past several years I have been using MusicBee with the latest available version, be that public release or "development", of every relevant BASS library posted at un4seen.
My rationale is that developers, be they Steven or Ian (the BASS author), update their work for a reason, normally to fix bugs, tweak existing functionality, or add new features. And like MusicBee's patches I want to be in on that. I fully understand Steven's reasoning on not wanting to be bombarded with tales of "viruses" due to the compression technique Ian uses, especially when his focus is on MB's management/presentation functionality.
So users are free to choose whether to update their BASS files manually from the un4seen site or not (unless they run the <sigh!> Microsoft Store version of MusicBee). The caveat is, keep in mind the versions supplied by the latest MusicBee package are the only ones Steven officially supports. Over the years I have done this I have experienced only ONE minor glitch; after a bass.dll update the small spectrum visualizer in the lower right corner of MB became inactive. This was fixed with a new bass.dll release a few days later.
As I have mentioned elsewhere, the newest version of a particular library may not be the one posted as a "public release" on the main un4seen website, but posted to "un4seen.com/stuff" in a zip package, e.g. un4seen.com/stuff/bass_aac.zip. Ian has officially described these as "'in development updates that are made available between releases. They are still 'release' builds and usually fine for production use."
Remember that making backups before any updates is always a good idea. And let me stray off-topic to close and recommend you also update tak_deco_lib.dll to version 126.96.36.199 if you have any TAK files (https://hydrogenaud.io/index.php?topic=120760