Can a Mining Pool Itself Rent Hashrate to Increase Its Share?

Yes, a mining pool can rent hashrate, but typically not to increase its share of the existing pool. A pool operator could rent external hashrate to increase the pool's overall size and therefore its probability of finding a block.

However, this is more common in the context of a pool temporarily directing its own combined hashrate, or renting external hashrate, toward a different, more profitable coin, often facilitated by a rental market platform.