The F1 cross of BFT X Sungold would be quite a small fruit, I expect. Possibly beef shaped, but not very large.
Making crosses does have a high failure rate but if you do lots of them you will get some to take. Don't give up.
Also although Sungold flowers are small, it's worth trying it out as a parent, you could try the crosses both ways. Some cherries make surprisingly good mothers, and are not too fragile to work with. Some plants IME are more sensitive about the emasculated flower, maybe they are more easily injured than others or have a reaction not to grow the fruit that they feel may be 'defective' or damaged. They will only wait until their best fruit have been grown up, and maybe then give it a try.