You will want to get out of the habit of using LOOP as a label, in PBP3 LOOP in an instruction.

Is is best to get out of an ISR as fast as possible, set a flag for the main routine if a long (time wise) instruction needs carried out. Using ON INTERRUPT gets around this problem and you can get around it when using ASM interrupts but you will find it troublesome. So I would get rid of the PAUSE in the ISR all together.