But with the ID nulling my rest mass, I won't regain my effective mass until somewhere around 1500g.

You read that right. And that's only regaining my "normal" effective mass, yielding my "normal" weight in a 1g field.

It scales much higher if my body can take higher "weight". I should be easily able to tolerate a continuous 5g in my present state, and 20g with some minor structural enhancements.

Which gets me into the range of 30,000g of acceleration.