If you can please try if in your phone testing everything will work fine with faster SD card (if you have 1tb micrSD), instead of using additional hard drive.
It would also be good if you have power meters to see how much power phone is using with node, and @simpic I would ask same thing from you.
I have already tested "smartino" with a 2017 phone and a MicroSD. All works fine and the power consumption is from 0.6 to 0.8 watt.
I am considering doing something similar, but old phones I have are with weak processors...
PS
What do you think is minimum specs Android phone should have to work with Smartino?
AFAIK you can have good performance starting with 2017 phones having Android 7, but but I would be happy to be proved wrong and see it working on older models.
I ran a bitcoin node from a Raspberry PI3 with IBD directly from the Raspi, with syncing time of about a month because of block validation.
I am. It scared of weak performances.
Definitely something I will test over this holiday season.
But I am already ahead of this.
Is it possible to run Umbrel on this setup? Raspibolt?