A Rogallo wing is an extremely complex exercise in aeroelasticity, understood well by far fewer people than "conventional" wings. What they're not is crude or necessarily poorly designed. The specific wing you're describing sounds to me like an
Air Creation Tanarg wing, or close relative, imported into the UK by
Flylight at Northampton Sywell.
The concept of the use of a Rogallo wing within a 3-axis control system was tried by a few manufacturers in the 1980s, and generally speaking abandoned. I can't offhand think of anything that's happened since to change that conclusion - although the elimination of top rigging in some of the most modern designs may make it possible to mount the wing below structure - not previously attempted. Checking the
usual databases it doesn't look like any of those hybrids made it through the mandatory imposition of
BCAR Section S in the UK between 1984 and 1987, or the similar BFU-95 in Germany a little later so data will be sketchy in the extreme. Almost certainly the best source of information will be a long out of print book called "Microlight and Ultralight Aircraft of the World" by Berger & Burr.
On basic characteristics of Rogallo wings, these are probably the most authoritative sources, some you can download, some you may need to buy, or quite possibly just use a library (the National Aerospace Library in Farnborough may be your best resource here!).
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf
https://www.amazon.co.uk/dp/18403728..._sl_anerc182_e
Book Review: Tailless Aircraft in Theory & Practice | UAV and Model Airplane Design, Building and Flying | RCadvisor.com
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf
You might also see if any talks by Dr. Billy Brooks of P&M Aviation in Wiltshire are on the web somewhere - he's certainly the cleverest man in the field in the UK, and quite possibly the world.
I'm going to hazard a guess you are doing this as a dissertation exercise in a university somewhere?
Will a microlight or hang-glider Rogallo wing be improved by the addition of 3-axis controls? I doubt it very much, but it's an interesting academic exercise, and I wish you well with it. There are discussions from time to time about whether the use of an external horizontal stabiliser may reduce the risk of a
tumbling departure, but that's unproven and all
current work on tumble resistance lies elsewhere so far as I know.
G
(Checking my logbook, 350hrs under a Rogallo wing, although no current plans to increase that as I'm busy flying other stuff right now).