Agree, 42mm is too thick to stick into a hole and be able to pin point which side has the object (unless you have massive holes and that's not the best for parks).
I've had 2 freebees when I got my detectors and have brought a Pro-pointer. The Automax is huge and next to useless. The Bullseye II is twice as good as the Automax but the Pro-pointer is in a league of its own compared to these others.
If I was starting off again I would forget all the cheap alternatives and just learn how to pinpoint with the detector then pass a hand of soil over the coil to find the target. Once the $1 & $2 finds got up enough I would then get a Pro-pointer - bypassing the cheap alternatives completely.
They are expensive - but worth every cent and if the finds pay for it then essentially the Pro-pointer costs nothing.