See my post above for info on how to get to them on Linux
There is no info on how to get to them on Linux in your post above.
The StrongHelp files are just an imageFS. In other words like a disk image that can be mounted on other OS's.
OK. How? Exactly?
I dissagree with sticking to a "current standard" of any kind. My reasoning is that we have lost just as many long standing standard file formats as we still have. There is no way to know for sure that a given file format will be easily accessable in 20 years time (and software can last a lot longer than that).
Disagree how you like. But if the format used ASCII and a markup like HTML, SGML, XML, JSON, MD, etc then at least any current computer could open it and display it in an editor. It would be human readable for the next million years, even if impressed as binary dots on clay tablets. We would have time to figure out how all the formatting/linking marks worked.
And as mentioned above there are multiple ways to get at the data in StrongHelp files.
As hinted at above perhaps. Please tell in detail how to do this on Raspbian, Debian, any other Linux. Or Windows or Mac will do.