Hi YoungBowyer,
I don't have as much experience as others with it but I'll give it my best shot. Many reflex there bows on a form that holds the entire length of the bow and clamping the bow in. I've done several with a "limb-length" form and make the form more narrow than the bow itself when using a heat gun, reason being, if the form is wider the heat gets trapped under the back and can scorch it. Don't be afraid of adding reflex "by hand" though. You can use Crisco to coat the belly and just heat the bow evenly until you feel it begin to "give" when bending in reflex. Hold it in position long enough so it begins to cool off before letting go of your reflex.
Recurves? I have trouble with them. It seems that it may be easiest to add them for many woods while it is still green. Forms for reflex seem to be built around more of the outer 3rd of the limb with most of the arc in the last 6 or so inches. A metal strip will help reinforce the belly when recurving so a splinter doesn't pop as easily. Also, you can go much thinner than many think on your limb tips and it will help to allow the reflex to bend without lifting a splinter on the belly (a problem I've had).
Perhaps you can PM someone if you've seen a specific bow that you'd like to mimic.
Good luck!
Parnell