https://eg4electronics.com/warranty <-- No mention of 80% DoD.It says 10 year warranty at 80% depth of discharge
Calee from Signature Solar also confirmed that going beyond 80% does not void the warranty.
From what I've learned LiPO is less susceptible to the micro-cracking of extreme charge/discharge than other lithium technologies. But I'm not a battery chemist so don't quote me on this.