already optimized the plugin list and currently only use the necessary cordova plugins.
for testing i also completely disabled all cordova plugins and the first start still takes significantly longer than any of the following starts, even if the app is no longer in memory.
however this only applies to low end android devices, neither iOS nor WP have this drastic difference in app start performance.
the affected low end devices are mainly still on Android 2.3.x, which is still used by quite a lot of users, appearently i have no access to "higher end" devices still running this old android version to determine if it is the os version or just these old devices themselves ...
guess this is just the way that low end devices are really slow nowadays