It is appreciated by the way. It makes my job much easier when customers understand that products are updated in cycles, and that we can't drop everything to do their exact request as soon as they want it.
This is not a complaint, or a request. I fully appreciate that it's not an efficient use of your time to be excessively backwards compatible and you've already done too much for us 3.7 dinosaurs.
It worked fine with the old vbookie/vbcredits addon anyway (though a bit of a pain to track down a new copy after I'd uninstalled it prior to attempting to install the new one, and then it refused to install because there was no 'old vbcredits' 1.3+, but I edited out the dependency check and everything's back to normal )
The "old" version is missing many hooks which the new actionset is dependent on. Obviously cant fix that without upgrading vBookie. Without those hooks, you may as well just use the old integration.