>> "The ability to recognise Docker runtime environment is quite critical for any (linux) software running in trial or activated mode - the main reason for using LimeLM."
Yes, it is.
>> "now it is February 2016 and waiting continues... well, delays in software development are typical, but..."
There were both delays and plan changes (including infrastructure improvements). Together that pushed the date back.
>> "Maybe it could be better to release critical fixes and improvements sooner - in smaller and more regular incremental updates of the library..."
Yes, that's what we did with the 3.x release. The 4.x is a big leap forward (with necessary API changes) and thus it required it's own release -- it wasn't something that could be rolled out incrementally.
The 4.x release and onward we will continue our trend of incremental releases.
>> "- Is there any way how to alpha / beta test TA 4.0 now?"
No, we're too close to release.
>> "- If not, what about to release a new minor version upgrade with TA_DISALLOW_SANDBOX inside, if TA 4.0 is getting more and more delay?"
We couldn't do that without, ironically, delaying 4.0.
We're well aware of the demand. We're working to get it out as soon as possible.