Jim, understood, and why I was broader than API and used phrase 'touch' points
I was thinking specifically of Exeldro's Media Control plugin (which is very important to my stream workflow, with its time remaining display on pre-recorded media). v0.2 of Media Controls works with OBS v25, and v0.3 and up works with OBS v26. When I upgraded OBS to v26, I got funky UI issues with the older plug-in, and had to update. [and with the implied BETA status with a 0.x version number, I'm okay with that].
I understand that a plug-in developer can use 'published/recommended' APIs, or sometimes will interface/hook using other methods [for whatever reason, some good, some not). And sometimes those connections or defaults change (or a plug-in author's assumption is no longer valid) ... and I understand and accept that [Granted many users don't understand the intricacies of s/w integration]
So, even when the authors of OBS (or any other S/W package) try not to break plug-ins doesn't mean that an end user is guaranteed that ALL plug-ins will work the same after an OBS {or other App} update... I would consider that an unreasonable expectation. The challenge of S/W dev is innovating and improving and trying to maintain compatibility... hard thing to do. I further understand that with FOSS, expectations I would have of a enterprise commercial vendor regarding testing, documentation, support, etc don't apply and that is ok.
Keep up the good work with OBS, it is appreciated