[Suicide Junkie]

That would merely slow down the growth... it'd still be exponential.

When you double the number of money-making ships, you can double the number of money-eating spaceyards that are producing more money-making ships.

As long as you balance the growth rate with standard races, it shouldn't be too much of a problem.
In practical terms its a similar situation to the Zero-maintenance races in Stock Classic SE4.