Using latest / newer ESP8266 Arduino version

No problem, I appreciate your work.
Thank you for the link, I’ll try it out but i need some time for this.

P.S: Why you don’t want to port that project to latest arduino?

There was a version for 9bit serial UART for 1.0.1 on which my project depends on.
The HardwareSerlal-library was changed since then and its far too complicated for me to port it.