Micropython is not making very many tagged releases; it has been over six months since the last one. Would you consider setting up a continuous integration branch on lv_micropython that syncs to micropython master once a day or so? This CI job would send email off to the littleVGL developers when the compile fails. That would allow manual fixups. There should not be a lot of compile failures, maybe once ever few months or so when micropython changes a core API.
I tried manually merging micropython master into lv_micropython today and got four or five compile errors. All of these are due to API changes in micropython. I’m no expert on micropython core so it is not obvious to me how to fix these. Note - if you made micropython into a subproject, that would eliminate the possibility of merge conflicts.
This CI branch should not generate significant work over the current model. Even though you are fixing up compile failures in the CI branch, this eliminates the work needed when micropython cuts a release. That work will have already been done in the CI branch, all you need to do is add a release tag.
Why do I want this? Because micropython is adding BLE support in the master branch. This BLE work is continuously being modified and extended.