This issue is only going to come up more and more with the prevalence of consumer NAS devices that run on very low-power ARM processors, little RAM, and may take 10 seconds just to spin-up from a hibernate state.
As a workaround I suggest using a more sensible timeout of 120 seconds instead of 45.
“I think even 120 seconds would be enough for most to sync properly. 45 is very short, especially as this could catch out ‘normal’ servers on a GPRS link. 120 seconds would still take less than 10 minutes for 4 sync attempts (and if it fails after 4 times the server is down).”
I am fully aware you will tell me to screw off but please at least consider this as I don’t think anyone would even notice this change (do correct me if I am wrong please) but it will fix DavDroid for a (growing) number of users.