Setting disk space watermarks for elasticsearch


We’re using SonarQube Version 8.7.1 installed on Windows
I’m interested in finding out if its possible to change the elastic search watermark settings from percentage based settings to byte size settings?
I saw some mention of being able to set values through opts in

I’ve tried setting values through there, and couldn’t see that they were having an effect on the elastic process. Is setting the opts the best/only way?
We have a fairly small scale installation/setup, but with the percentage based settings it means needing to keep a chunk of empty disk to keep SonarQube running.

Thanks for any help and advice you can provide,