Being that the cross is nucellar seedling of Miyagawa from a controlled pollination with Poncirus trifoliata I'm surprised that it has such a sweet and pleasant taste due to the P. trifoliate parentage.
If it's a nucellar seedling, then it wouldn't actually have any trifoliate ancestry.
In some cases, pollen from another citrus variety can induce fruit set, but those seeds in the fruit will not necessarily have genetically arisen from the genes in the pollen.
You might read the topic "What happens if you try to breed Triploid citrus" for further information.
"Nucellar" generally means the embryo arose from the surrounding seed coat (rather than the zygotic germoplasm) and is a genetic clone. Although of course sometimes there are mutations, and sometimes "nucellar" can (not completely technically correct use of the word) refer to multiple seedlings arising out of the same seed, even though sometimes one of the seedlings is zygotic (result of sexual recombination).