Had a quick look at one of the lights and it looks like it could use a teensy bit more exposure...so what I'd suggest is try, say, 50-60 seconds. If you find the Trapezium stars are then blown out, dial it back. M42 is such a tricky target to practice on
Obviously you'll know this as you weren't guiding, but there are mucho star trails. Certainly check your drift alignment more closely as I wouldn't expect to see such long trails in that time period on a HEQ5. Check your balance too as that could throw it off too
The thermal noise is also a problem, but that's a warm summer night problem
