Did you already forget the problems that quickly arose in v10 as soon as v11 became the latest release? V10 is still very broken. It is not even possible to install a fresh copy of v10 as a production server (and YES it too is still a supported version).
If you really think that it is safe to ASSUME that you will be always able to easily upgrade from v11 to v12, then you have not been following along as the ever increasing growing pains of this project progress through time.
There have been periods of months long agony when the upgrade process from v10 or v11 was broken, then fixed, then broken again.
It is always better to be prepared for the worst while you pray for the best. However, the evidence is very clear. Once a version is not the focus of the core dev team, then only community provided fixes are even “considered” (not necessarily even merged).
Since the bulk of the developer expertise is in the core team, very little will ever be fixable by the community due to the heavy burden of getting PR’s past the approval process.
So, now knowing the status of the project, I would always suggest to try to work within the current focus version and work aggressively to get the problems of that version fixed through the attention of the core dev team. If you find this to be to difficult for you to manage, then you should probably consider using some other ERP system.
I do not necessarily like the options myself, but I believe the project has a better chance of getting better over time than it does of dying altogether.
Again, just my opinion and as always,
Your mileage may vary…