However, there's a benefit in this case: heat shield probably scales with area (often something like mass^(2/3)), making it progressively less significant compared to fuel mass (which is roughly a constant fraction, i.e. it scales like mass^(1)). I think a high altitude launch site could make a significant difference as well (although that creates other logistic inconveniences). Atmospheric pressure approximately halves every 5km, and air resistance is roughly proportional to pressure.

It would be more efficient, if they could use a whip effect to (match impedance) capture much more of the rotational energy they put into the spin, more like a trebuchet.