It is ok to do as a novice beach hunter or a person getting used to a new metal detector, but only digging two way repeatable signals will cause you to leave valuable targets behind for the next beach hunter.
There are many ways a good target will not respond from a left / right and vise versa sweep.
It may be a coin on edge, broken band, gold chain, unusual metal mix, iron masking or a target being masked by a larger object that is the reason for a target only responding from one sweeping direction.
Target depth also has a lot to do with the way an object will respond when you sweep your search coil over it at the beach.
Beach hunters have the disadvantage of not being able to rely on the " Halo" effect a coin or artifact buried on land will often have.
Recently lost jewelry or coins at the beach could have sunk at any depth in the sand and in any position, especially on the lower beach and in the surf zone.
This area of the beach is constantly changing and churning over stuff we are searching for.
Only stopping to dig two way repeatable target responses is ok, but targets on the edge of detection range hardly ever sound good until you have removed a few inches of sand.
You can place a gold ring next to a clump of iron or a large nail and I guarantee you will only hear the gold ring sweeping your search coil from one direction over the iron object.
You may not hear the gold ring at all, if you do not sweep over the two objects slowly.
Only digging two way repeatable targets is like only going to the beach two hours before low tide, both lead to missed opportunities.
This superb antique gold ring with jade and diamonds was just a crab fart signal response from one direction at a Florida beach with a shipwreck from the late 1800s.
If I only dug two way repeatable signals, I could have easily walked away from an antique ring that appraised for $7500.00
Something to think about the next time you only hear a slight signal from one direction when sweeping your search coil.