Motor heating issues after PID tuning - D-term troubleshooting needed

Build specs: 5" freestyle, T-Motor F60 Pro III 2207 1750kv, SpeedyBee F7 V3 stack, 6S 1300mAh. Recently tuned PIDs following Oscar Liang's method but experiencing motor heating after 2-3 minute flights.

Current D-term values: Roll 52, Pitch 55, Yaw 35. Too high of D term can cause motors to get hot. Do a short flight, 10-30 seconds, land and check motors. If you can hold your finger on the motors then they are not too hot. Motors are definitely too hot to touch comfortably.

• Reduced D-term by 20% - still heating
• Enabled RPM filter, bidirectional DShot confirmed working
• Props balanced, frame tight

What's the systematic approach to isolate this? Should I suspect filtering issues over D-term values?