Is there a way to set suspend on ram, like what purism did to the L5? It seems to improve battery life a lot.
The PinePhone should already be set up to suspend to RAM on inactivity. I have not checked whether Mobian sets it up correctly, but in principle any PinePhone distribution should be set up for it.
Hibernate (suspend to disk) is not possible without a physical swap partition, and since the PinePhone distros apparently all use only zram for swap (because swap on SSD tends to wear out the SSD, that goes for both the eMMC and any microSD card), there is no way hibernate can work. So suspend to RAM is the only option, which everyone should be using already.