Some good suggestions Ian
.
You are offering ways of checking against the rules, which is the vital step that some definitions miss out.
I think a major point about a long self bow like a warbow is that the limit is the performance of the wood.
If anyone tries extreme reflex, they are likely to run out of draw length.
That's what I like about the ILAA spec (not a warbow spec' as such), it is well documented with a rationale explained for each definition.
I really like your rule applied to the back of the bow and no more reflex than so many inches (or mm) gap.
I'm currently working towards making a couple of warbows to ILAA spec with some deflex in the middle and right reflex in the outers. Overall the tips will pretty much be in line with the grip and hopefully they will have a smoother acceleration (this may just be bowyers optimism
).
I think the flatness/roundness is the big stumbling block if rigorous examination is undertaken. Many staves have concave features or grooves in the back which go from rounded to flat and even concave.
It need sto be worded very precisely, like:-
The back of the bow shall have some curvature across it checked against a reference profile for at least 80% of it's length.
A straight edge could also be used (as it is more readilly available), if the straight edge rocks rather than sitting flat across the back then it is curved.
The devil is in the detail and if it's not precise we can fall prey to pedants.
Regarding arrow weight, there should IMO, be one of the standard heavy warbow arrows and an "as light as you dare"
class to allow for absolute maximum distance.
The lighter warbows would be better shot as longbow class as anything under about 90# will struggle with a "standard" arrow.
Del