I usually end up cutting vertical area, when the propensity to an uncontrollable spiral dive... not a spin, occurs. There's too small (spin) AND too large (spiral dive) for verticals.
One of the SAE planes in 2000 never made a successful takeoff due to lack of vertical area. It swapped ends every time the wheels left the ground!
I have more trouble with spins with an aft c.g. than anything else.
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That 120 foot distance IS an amusing limit, init?
Need to add lots of lightness.