Presuming even with signing up on day one that there will be plenty ahead of me, the subsequent presumption is that a few will be delivered before I'm asked to commit my order. If the first few deliveries suffer from the same quality/build issues reported in the X forum, I'll cancel. Not worth the $3,750 savings from half the tax credit.
Second, there's no need to be concerned with supercharger availability. 90% of owners don't use SCs now. Figure 60% of M3 owners won't either. The handful of SCs under pressure now are fine 90% of the time. There will be no spinoff, no subscription model, and no pay per use.
Given the fact that the majority of M3 owners won't use SCs, I wouldn't mind seeing a base model without SC access enabled, but available later for some additional amount. Remember that Iacocca's Mustang launched with no radio as it was intended to be affordable for families.
We shall see.