Excuse please, if I've missed it above, but has anyone mentioned the obvious..... we send you direct, then make it a heading... because it suits us, and hopefully you too !
To set up one a/c on its desired track, but locked on that track by making it a 'radar heading', whilst you vector a second one around it (same or opposite direction), means that at least one party is pointing in the right direction when the vectoring ceases to be necessary.
I've always thought that made good sense, and helps the crew, but it will be influenced by airspace layout, climb/descent profiles, etc, so is not always appropriate.
Just my own thoughts as I strive to be helpful.
