It really makes our job easier when you have a backup plan for your electronics because it avoids a lot of conflict. Also.. we totally understand it sucks when we take your bag to check it.
and i always come with two bags. one is laptops and the other is a musical instrument. i would not allow you to check in either.
1. Double check the rules before you go and verify everything you are taking is allowed.
2. Purchase some sort of ticket that has priority boarding (also make sure you are at the gate enough time ahead to take advantage of it). First / premium economy.
3. If we run out of space and you must check something. You may be upset: If you argue, and escalate the situation- it probably won’t convince us of anything, we will just call the police and have you removed from the flight. 99.9% of the customer services agent (and their supervisors) job is defined by clear procedures that they have no control over.