Compact Flash/USB Install for Low-Power Application

Hopefully I'm posting this in the correct location. I'm working on a UTM build and have narrowed down the choices to either Sophos UTM Essential Firewall or pfSense. I'm trying to drive the power consumption as low as possible since the device will remain powered on 24/7. One of the ideas I had was to use either compact flash (CF) or USBjump drive as the bootable source for the OS in lieu of a traditional spinning platter/SSD hard drive. The obvious problem here is that CF/USB flash are write limited which is problematic for an OS that is constantly writing logs.

pfSense has a CF/USB variant of their OS that is designed to maximize drive life. More details here (https://doc.pfsense.org/index.php/Full_Install_and_NanoBSD_Comparison)

I was wondering whether or not it is possible to install Sophos UTM Essential Firewall onto a CF/USB flash drive and if so how would I go about configuring in such a way that it doesn't kill my CF card (like keeping the logs in ram and maybe using a syslog server on the network to rotate the logs?).

Thanks