Hi, I really understand you and it is hard to explain all the reasons why things work like they work.
1) After I switched to core joomla update feature, I get enormous problems for the extensions because the core update feature is not perfect - you can just see this forum, there are a lot of problems caused by standard joomla update feature
https://www.phoca.cz/documents/16-jooml ... extensions
https://www.phoca.cz/documents/16-jooml ... m-manually
The upgrade/install functions worked different way, they checked a lot of dependencies, etc. so there were no such problems like they are now
2) But yes, I just switched to joomla core update system and all the new versions will get this feature
3) "some emergency security fix" - hard to say, there was no emergency security fix in 10 years of Phoca extensions (I hope, this will not change after this sentence

)
So, yes, all new extensions, all new updates of current extensions get the joomla core update system (although is brings more problems) but it takes some time until I update all the extensions I made. And maintaining the joomla core update system takes a lot of time resources, so it can happen that because of loosing time with the maintaining this system, some new features will be not added or even there will be not time for extreme security tests I do for now.
The time is always limited and priority must be set. To be honest there priority is not using the core update system, the priority is:
1) security
2) making the extensions ready for newest joomla (really hard task because Phoca extensions are fully integrated in Joomla! and every change in Joomla! has deep impact on the extensions - and if you made over 130 extensions, it is extremely hard to have them all always ready for newest Joomla!
3) making it ready for newest PHP, SQL, external libraries, etc.
In perfect world, all the task will be on place number 1) including implementing the joomla core update system, but what would you prefer, in case the time is limited:
a) all the extensions are ready for the newest joomla but users just should get information about update through extension's "check for update" button but not through the joomla extension manager
b) only few extensions work in newest joomla but they have full implemented the joomla core update system
And what if b) and the extension you are using now is not the one which is updated? So it does not use the joomla core update system but it does not even work anymore
Really, it is not always so easy as it looks
Jan
Jan