Probably succeeded to have it.
It was done with castrated PTP flowers pollinated by Valentine pummelo. I tried also another way, but failed.
This year was supposed to be the last to try any cross with PTP, previously the seedlings although different in vigor were rather uniform in the shape of leaves and overall look alike.
Now only one third of them (I am germinating 85 seeds) look like those of poncirus, the rest are clearly different.

Putative nucellar seedling to the right. Red arrows point to the tiny unfoliate alternate first leaves typical for pure poncirus seedlings.