I can’t speak for the Gaias use for speakers, but with the Oreas and my integrated and SACD player, going up to about 90% of the weight limit didn’t sound as good as going up to the next size and utilizing about 40-60% of the weight limit. The difference was noticeable.
I would assume that both Isoacoustic products are designed with similar values to be used.
All the best,
Nonoise