ETA: this statement is based on reading technical literature and not actual testing. I like to make medium size fillets.
The main strength of a properly brazed fillet is in the thin area between the tubes. You can replace some of that strength with big fillets. In conclusion, big fillets are stronger, but you probably don't need them.

I noticed in your pictures that you were having a bit of a problem building a fillet; wouldn't hurt to do the tower building exercise where you try to build a tower just out of bronze. It's worth the time to get that control and then you can decide how big you want to make them. You can also just add flux to your already made practice pieces and make them bigger to see what happens. There is a fine line between a perfect fillet and a collapsed mess so practice is important