Which has a better flow rate ? FRAM Ultra XG 9688 or ...

Hard to say not seeing any delta-p vs flow data for the Hyundai filter. But there is flow data on the Ultra and it's low like most full synthetic media oil filters. If I had to bet, I'd say the Ultra flows better ... which simply means it has less delta-p across the media when oil flows at X GPM through it.

With a positive displacement oil pump, if one filter has a few PSI more delta-p it's probably not going to make any real difference to the motor.

From the @Ascent Filtration Testing thread in this forum. The lower the curve, the better it flows.

Hot Oil Flow vs PSID Comparison - Annotated.jpg