I'm happy to announce that the youtube-subscriptions plugin just got navigation support (*yay*). You can now use MediaNavigation (or the regular FF/Rev buttons) to jump ahead or behind in your clips.
It took a lot of time before I understood what needed to be done, but it was fixed with just a few changes of code. The new proxy version is on svn. You should reboot your devices to update to the newest version.
In case of trouble, post back on this thread and I'll see what I can do. I've tested it on 1.02.21-wdlxtv-0.4.5.3 as well as 1.02.21-wdlxtv-0.4.3.1 and I've had no problems with it. Even resume points work