Hi @nigel, and welcome to the community!
I’m rather limited on time so please excuse my rather brief and dry answers. This area is @phillxnet’s expertise, but I’m wondering whether you are running a Rockstor version dating prior to the addition of your product ID as a fake appliance ID, hence you are not benefitting from this addition. If this is the case, and if you’ve just installed, it might be a good opportunity to try out our new Rockstor 4 version. While we only have a DIY installer for now, it might be a good choice here for you; see @phillxnet’s post in the thread to which you linked, for instance:
If you are indeed running Rockstor-3.9.1-0, it will represent a very substantial update for you as that version is now very old. There might be the option of manually adding your UI (as in the code to which you linked) to your local file and restating the rockstor service but I’ve never tried that so I’m unsure of the consequences.
Sorry again for being very brief and probably not as helpful as I would have liked, but I do hope this still helps.