Build rules (section 2) refers...
2.2.
Legged Robots [Walkers] can weigh up to twice the specified weight in all classes. A
walker must employ moveable legs to support its weight. Robots with rolling or sliding
mechanisms will not be classified as walkers.

To be honest I'm not sure that a device capable of gyroscopic progression (as you discribe it) would be classed a a 'true walker' in the spirit of 2.2 above. However before any determination could be made I would need to see a set of drawings or a working prototype.
I would love to see it in action as it sounds like an interesting engineering idea, regardless of wether it actually complies with the build rules for a walker or not!

Geoff Smith,
FRA acting safety officer.