Switching employer immediately after I-140 approval

[MLFQuestioner]

Many suggest that one should stay with employer (petitioner) at least for 180 days after I-140 approval. Can the beneficiary resign and move to a different employer within 180 days (in fact within 3 months) after I-140 approval  without affecting the priority date that got approved with his existing employer?
If one can, what things one should consider while moving to a new employer within 180 days after I-140 approval? Like should the current employer be requested not to revoke I-140 until it is 180 days, new employer should file Green card immediately after transfer etc.