Congrats on the cute kitten, Alassariah.
Just as a reminder though...
Aussie Dark Chocolate is currently within the range of recessive to Aby Black Silver and Dominant to Tonk Tortie, according to the Saga charts.
So there isn't need to repeatedly test mate it against furs outside of that range, since those relationships are already known by default. Tonk Champagne falls well above Aby Black Silver on the D/r charts so would of course also be Dom to Aussie Dark Choc by default.
Thank you so much for wanting to help & for sharing information. Perhaps test mating your lovely Aussie against a fur that falls within the known range might be a possibility?