Two things strike me:
1) Oxycontin is supposed to have a 12hr duration, though I know it is often prescribed 3x daily because the last few hours wane in efficacy. 4x, though -- I haven't seen it.
2) Since you're taking 80mg through the time-release mechanism, 5mg for breakthrough is very meager. You should be sufficiently tolerant because of the dose level of the oxycontin that another 5mg of oxycodone seems trivial.
If you want to stick with your PCP, maybe discuss 20mg 3x for the oxycontin and up the breakthrough to 10mg. Since you're now taking approx 85mg/daily, if you think 20mg 3x for the oxycontin is an option, then you would have approx. 15mg for breakthrough.
If you don't think that your PCP will consider it, then maybe discuss a compromise: get a regimen set up by a PM, but managed by the PCP? So, you might only need to see the PM to consult when something needs changing, but your PCP is the prescriber?
C4-T4 Scoliosis (disk degeneration, stenosis, narrowed neuroforamen, bone spurs), RT hip and SI joint damage from car accident. Also, pectus excavatum, supraventricular tacycardia and mitral valve prolapse syndrome.
Current meds: Ultram ER 300mg & 2-3x 10mg Hydrocodone daily. Oxycodone 10mg for BT. .25-.5mg xanax as needed for sleep, Verapamil 240mg SR (for tachycardia).