I agree with TEP that the IMM is course specific, and no IMM is universal to the way the game should be presented on diverse styles of courses.
When deciding IMMs for courses built many years ago, pre- I&B technology, pre- maintenance equipment technology, pre- irrigation technology, we must strive to interpret what the archie would like presented. We must compromise or cope with seasonality, and we must take care that time alters growth of things like trees, and even evolution of soil functions, all effecting either the strategic or performance of ball and ground relationships which ultimately alter the archie's original intent.
To that end, we must also consider that some archies, past and present, DON'T EVEN PLAY OR UNDERSTAND THE GAME, to varying extents!
IMHO.
There are archies out there who past and present designed golf courses like parks and tea gardens, never really giving a thought to the ideals of the game. I doubt some of them even thought of the functionality of firm and fast. They just designed for pretty, sizzle to sell communities, and calander shots of their landscape.
Take all the best archies working today. They all either understand the game, its craddle, and/or play it reasonably well. I can't think of any I respect that don't have an IMM that leans towards F&F and don't incorporate F&F features and strategy foremost when designing approaches and surrounds. I can't think of any great modern designs that don't lean towards more width in LZs and elasticity in teeing grounds, that bring bunkers and hazards into the equation, with F&F conditions likely being available most of the time, except extreem wet and or overseeding seasons.
I think that going forward, any archie worth his salt ought to submit a hole by hole analysis of his intent of how the course should be presented in an IMM, and describe and specify things like placement of hazards, mowing patterns, irrigation, and ball and ground functionality, for the high handi and low man. Then, the archie ought to also discuss the intent when the course will experience 'less than IMM' with due consideration to the realities of seasonality, southern summer turf dormancy and needs to overseed, wet and drought response realities, and even drainage performance.
That may be a tall order for an archie to submit all that to the 'as built' documents, or just as an accompanying narrative to the turn-key grand opening, for those future supers, owners, committeemen to have as a guide. But, it sure would go a long way towards taking out the speculations of what are and should be IMMs, as being discussed above, IMHO.