Trying again to understand addon-installation in KM.... sigh... still a hard struggle...

CookieKeeper is great as example, because the author included native KM-support, and it even creates a menu itself!
http://kmeleonbrowser.org/forum/read.php?9,131507

In the xpi in install.rdf the min-version for KM is set to 75.0,
and the min-version for Firefox to 38.0 (=KM76)
Latest findings:

------- kmeleon.install_firefox_extension = FALSE

- normal FF-addons are BLOCKED , having KM not defined in install.rdf
- KM75-76: cookiekeeper works fine out-of-box (only the xpi-name must match the ID defined in install.rdf)
- menu works too! (in Tools at bottom)
- the menu opens the options page in a new TAB
- the Options-button in about:addons opens a new WINDOW, which is cropped too small and not resizable (just Vista?)

------- kmeleon.install_firefox_extension = TRUE

- other addons work fine (more or less), thinking this browser is a Firefox
- KM76: cookiekeeper works fine, but NO MENU
- KM75: cookiekeeper is blocked as "incompatible", because install.rdf wants Firefox min-version 38.0 (=KM76)

-----

Have struggled to find workarounds to ignore the FF-min-version in KM75.x, tried half a dozen gecko prefs meant especially to ignore compatibility versions, but no chance.
Finally gave in and edited the FF-min-version in install.rdf:
now cookiekeeper-addon shows up in KM75 too.
Still, no menu, due to the FF-fake-pref.

Of course, this menu can easily be added by a little macro, just 2 chrome links, but would really have liked a way to globally ignore that "min-version" prob
The one thing I have not tried yet, is this FF-addon, to disable Add-on Compatibility Checks:
http://kmeleonbrowser.org/forum/read.php?9,133880
Everyone praises it in the web, and guenter uses it in KM, but still, would just greatly prefer a simple pref-solution.