Are you located in the US? 400mg of Morphine is a lot, most doctors here claim "we can only prescribe MME 90mg" (either 90mg of Morphine or the equivalent, like 60mg of Oxycodone) Also, which breakthru medications are you taking?
As a near lifetime opioid user, I will be brutally honest with you brother. Suboxone is a way to override our receptors so we can not feel "high". Now, Butrans is a funny version of Bupe. It is a transdermal formulation that, even in its highest dose, does not fully block full opioids. It manages pain exceptionally well, but it will not replicate the euphoria or immediate relief of your Morphine. Unfortunately these patches are also 7-day patches so applying more than 1 will leave you in awful WD toward the end of the month.
Are you trying to infer if the Butrans will work well with your current meds, or if it will be a suitable replacement once your doctor retires? Butrans and Oxycodone was my absolute favorite combination. The norbuprenorphine levels remain pretty high so you are able to get both pain relief and the euphoria associated with opioids. Combining the Butrans with your Morphine will do the same thing. I liked it better than Fentanyl! Bupe is a very good painkiller in small doses and doesn't oversaturate our receptors like the insane dosages doctors love to prescribe of Suboxone.
I am praying that you are able to find a replacement doctor once your PM doctor retires that will understand and treat your pain properly. As a replacement for the Morphine alone, you may find the Butrans lacking in its' painkilling and analgesic properties unfortunately. I would suggest lowering your dose and then starting Butrans. Again, praying for you brother. I know how unfair this epidemic is for genuine pain patients