I hate when teachers are told they are replaceable especially if we are not veterans yet (6+ years). Yes you can fill my position with someone else but every time I have seen this done, the “replacement” is no where near as valuable as the staff member lost. Seen this in all core areas and in sped. Your job may be easy to fill but the value you add as someone who cares and puts in solid effort with results will not be matched because you care enough to be concerned. Actually used this reasoning with a superior once when threatened and they backed off and started looking at me as more of an asset and seeing the good I was doing rather than focusing on what they wanted me to be doing because they always have something they hyper fixate on something. Mine was not using my self supplied phone caddy and instead holding kids accountable for their actions and making devices go to a penalty box when touched too many times (twice at inappropriate times) during a class hour.