Windows-linux 2:1 is very close to what I expected to see.
One third is a massive customer base.
Modern software development practices emphasis cross-platform whenever possible. If you have competent people working for you, the extra cost of supporting both Windows and linux is negligible.
If you choose to only support Windows, it's basically saying "f*** you, we are not interested in being helpful, cope." Those using linux mainly will cope and work around the limitations you gave them, but it will cost them time, and if available, they will turn to a competitor who offers the linux tool once available, so you are at a risk of losing the business.
OTOH, if you only decide to support linux, you are completely locking out some part of Windows users who are just unable to cope because it has been traditionally possible to work on Windows only so they never learned to work around.
All in all, for the widest audience, you absolutely must support Windows but not supporting linux is likely a very bad choice, so do support both.
In best case, all your tools/UIs/codebases except embedded core itself are written in such a way that providing support for all major OSes is a matter of running compile, running a simple unit test on each system, and packaging the files.