First off, why do you answer texts from your pm? We are not required to even have a phone, let alone use it for "Business use" as a carrier, unless the USPS provides us a phone , like your pm.
Get back to the office and if he wants you to take it out, do it on a 2nd trip charging him 3 min/mile to do so. This will soon stop. After you are told to take it out switch your scanner to "pm casing" and start "load vehicle". Some carriers (in these rare occasions) have been know to "forget" to stop the loading time until they deliver that parcel, "Oops". Then hope that the parcel that the clerks MIS THREW (This is the reason the phrase "Clerical error" was invented) was for the furthest part of your route. 3 minutes/mile for 30 + miles will ruin your pm's office budget if done often enough, and will increase your route evaluation due to extra load time after awhile. The way to stop any "New duty" your pm can think up is to charge him for it through form 8127 or green cards if you're an Rca.