It kind of has to happen *sometime*, though. I know automakers do this "earnings massage" swinging of inventory, but it's really inefficient and a drag on long-term cash flow and profits. (You have to size the entire delivery pipeline, including store employees and storage lots, for *peak* operations rather than *steady state* operations.)
And you can reduce that peak sizing, if you design the overall system to operate in something more like a steady state rather than batches (which I know that you know).
The way I see it - if Tesla / Musk really do only care about the long term (and I more agree with that premise than not), then a logical extension from that is to ALSO report average working capital through a quarter, and/or average delivery days (days from "vehicle shipped to vehicle delivered"), or some other metric they have that they use and we can use to track working capital.
Something better than the working capital at a single arbitrary point in time that can also be easily gamed (namely, working capital as of the end of the quarter).
I realize it's gamesmanship that is practiced throughout this and other industries. It also looks to me like if Tesla explains their metric, and explains why they're focusing on keeping working capital efficient at all points in time rather than optimizing for single points in time every 90 days, that's an explanation that can then be tracked quarter to quarter AND that the long term shareholders of the company will buy into and support (the shareholders that I believe Musk cares about).
More broadly, I think that pretty much any company choice about how operations are run can be explained and supported by shareholders. The ones that disagree strongly will vote by selling, and the ones that agree will vote by buying. (Of course, assuming that the company is doing something that's smart from at least 1 point of view). For this reason, the company's current preference for optimizing operations around a single point in time that occurs 4 times a year (support from the rest of industry, easy to explain, number provided has the best visual appeal) can also be defended.
I think Tesla could change operations, explain the how and why, and the market would reward them for it. Maybe not immediately, but within 2 quarters. Especially if they showed how the optimization for the quarter end number caused the average working capital number for the quarter to be artificially high compared to an operations workflow geared towards smaller swings.