Default running dex2oat by hand ?

hi guys,
I want to work on the ART compiler of Kitkat, but I dont want to enable ART throughout or something, so here is my question:

Can I invoke dex2oat on a specific APK and run it ?

Second, a more bluesky question - is it possible to backport the runtime (I see it here) to run on older android versions ?
Phone : AT&T HTC One XL 2.20 rooted & S-OFF (proudly funded the bounty) running CM 10.2/Android-4.3
Backup Phone : T-Mobile HTC Mytouch 4G rooted/s-off on RoyalGinger