In all honesty, while I will never ever purchase any product from NDSP, as said, I absolutely don't understand why they don't just put an end to all this.
For a start, be honest and tell your users plugin compatibility wasn't working well and likely isn't ever going to. Yes, plenty of them will get angry (be it for real as they expected this or just on principle because it was promised), but NDSP could sort of easily come up with some compensation, namely an update to a) considerably add all kinds of models (amps and effects), b) feature an editor and local file management and c) improve usability. That'd instantly turn the QC into a very competetive and attractive product. And if they wanted to be really clever, they'd come up with a kind of answer to IKMM, such as in releasing a plugin that'd load your QC captures, obviously free for QC owners. IMO that'd add some considerable value to their ecosystem.
However, all that ongoing "we don't know and have to suspend things - but we're still working on it" while constantly releasing plugins and plugin updates is doing exactly the opposite, users simply feel shafted. And understandably so.