You are probably not losing as much depth as you might think because Multi IQ can compensate pretty well for a less than optimal ground balance because the multifrequency interpolation can readily separate a target signal from the ground phase signal. It is not as good as a precise GB and continuous tracking, but it compensates pretty well up to a point. As long as the ground is just trashy and not heavily mineralized, you should be ok. The way you can tell if you are losing a lot of depth by keeping GB set at 0 is to put the Equinox in AM mode (using the horseshoe button). If you are a getting a lot of ground feedback noise as manifested by a lot of -9, -8, -7 TIDs and ferrous grunts, then you should try to find a place to GB.
Besides, if you really can't find a coil-sized spot where you can pump your coil, a precise ground balance is probably not going to matter much as far as depth is concerned, quite frankly. In junk that thick, getting significant depth is pipe dream because of all the junk target signals that interfere with penetration of the transmit field much more than ground feedback noise.
If the trash is mostly modern mid-conductors like aluminum, you can try tracking GB and see how that does. I would not recommend tracking if you have a lot of ferrous junk, though.
HTH