i think i would define the standard objects a little bit wider.
for example: standart balance object must be shorter than 60cm, the upper quarter of the object mustn´t contain more than half of the weight (to prevent super top heavy objects) and the diameter of the balance point musn´t be bigger than 0.6mm
this way the juggler can still make prop decisions and i wouldn´t be surprised if in alot of cases if jugglers would decide for the same object but it´s a little bit more open to jugglers, who for example prefer to balance stick like objects. I also like that with an open definition changes in prop styles that happened in the past and will happen in the future are diminished.
and i believe a balancing object is rather easy to define.
how long and heavy must a standart club be. I believe most attempts to define a standart club would come to the conclusion that willy is not juggling a standart club and maybe super heavy oldschool clubs are ruled out taking away valid records of the past which were attempted with lind clubs.
with balls it´s even more complicated... must there be different categories for russians and beanbags...
should there be different categories for diabolos with a free axis...
I believe with an open fair definition usually the optimal prop will win the record darwin style anyway so as long as all props that have a real unfair advantage over another one are ruled out i would prefer a maximal open standart object proposal
I think alot can be learned from the many failures recordsetter makes
I remember a incident when an original competitor statet in the rules that "a standart devilstick of 80cm has to be used". this lead to some outrage and the conclusion that any stick would be fine which showed the other big problem which was that they don´t differenciate between flowersticks and devilsticks.