[cts_casemod]

Astro,
I saw that on the past so perfectly viable. Perhaps you want to make it high tech and add an electronic switch just to avoid the startup 'kick' (should be significant without the ice).
I was going that route but i had to take the starter ring to fit my adapter.

Regarding the noisy setup, its not that noisy, its AC and needs a reluctance sensor transducer to read the signal on the zero crossing point. The amplitude is not constant. Or replace that with a hall sensor, with built in logic.

P-hack,

let me clarify my point is observation of the motor parameters under field weakening operation. Feel free to provide stuff you find regarding that operational range (PFC, Slip, etc)

With that in mind, slip is proportional to torque, but not in the same way as during the constant torque/constant flux region. Look at Paul example using the FOC.

Ask yourself what causes the breakdown torque limit. That will help you understand why those concepts are not linear above nameplate.