@kshnurov I understand your frustration, as I have also experienced the lack of maintenance for some Elastic components that we have been/are still using.
Unfortunately it doesn't seem like maintaining all of these open source components is necessarily someone's full time job - I think in a lot of cases the maintainer has moved on to other projects within the company and maintains the repository only as much as his spare time can allow.
Thankfully, since it is open source, you don't have to wait for Elastic to fix it - you can fork the repository and make the necessary changes yourself. We have done this for several components, and while it does force us to maintain our own fork and periodically "sync" it with Elastic's version, it also gives us the agility to fix bugs that would have otherwise blocked us from using the component at all.
We have done this with the Logstash ElasticSearch output and with the ElasticSearch Spark connector, and will probably have to do it with the logstash clone filter as well (as it has a major bug that is being ignored).
I think your time would be better spent if you went ahead and fixed whatever needs fixing, and adapted it to your needs.