The FounderPool website specifically mentions:

> You contribute 1% of your equity into your pool.

My understanding is that if a founder owns 30% (say) of the company when they join the pool, they would contribute towards the pool a number of shares corresponding to 1% of that 30%, i.e. 0.3% of the company. Which will presumably get further diluted by the time the company exits.

Having founders contribute X% of their equity at the time they join the pool is more reasonable from a practical execution standpoint than having founders contribute X% of the company the time of exit.