meshtastic lets you use up to seven hops, but they don't suggest doing it unless you absolutely need to.

What can happen if your hop count is too high is that you cause a packet storm where you send out your packet and then you hear it again later and you retransmit it over and over and over again until the hop count finally runs out in a big loop.

Say you have nodes A, B, C, D, and E. U transmit, B transmits, C transmits, D transmits, E transmits, U retransmit, B retransmits, C retransmits, D retransmits, E retransmits, etc. etc. until it finally runs out.