UCC28C43: How to Handle Push-Pull Transformer Leakage Energy Without Overheating or EMI?

Tool/software:

In a push-pull isolated DC-DC (UCC28C43 + UCC27714 + NexFET), transformer leakage inductance (~1μH) causes:

• Obvious high-frequency spikes;

• Snubbers reduce noise but severely increase MOSFET temperature.

Questions:
 Any low-loss methods to manage leakage energy?
 Recommended active clamp solutions or other improvements?
Thanks!