Tracking codes are really not meant for this purpose. I seriously doubt you will see a feature added to automatically create a P&L report divided into 85 or more categories. Tracking codes are intended for divisions of the business, despite the fact that they can be used creatively in other ways.
Businesses define profitability in many different ways. However you do it, and whatever parameters you include, I can promise you there are dozens, possibly hundreds, of ways others might want to make such a calculation. Accounting is one thing. Analysis of accounting results is something else. Trying to anticipate all possible analyses users might want would result in terrible software bloat.
Only for those who are misusing the capability. And instead of customers being spread horizontally across many pages, your income and expense accounts would be.
I think most accounting professionals would agree it is unrealistic to attempt profitability calculations on individual customers when there are so many. A few categories might be meaningful, and for that you could use tracking codes. 85 customers (and presumably growing) is not so realistic. The effort of apportioning expenses across 85 customers in a rational way is just too great. If this is, in fact, critical to management of your business, Manager is probably the wrong software for you.