These are the only modifications I made.
I do have to (because of my dac) enter dtoverlay=hifiberry-dacplus in the userconfig.txt, see the link for why. maybe it has something to do with that.
I always unzip the zip file.
ps, when I use the same SD card with the regular volumio, no problem with updating.
boot/userconfig.txt
# 7,9 inch hdmi touchscreen
hdmi_group=2
hdmi_mode=87
hdmi_timings=400 0 100 10 140 1280 10 20 20 2 0 0 0 60 0 43000000 3
# ian canada FifoPI MA
dtoverlay=hifiberry-dacplus
# power off button
dtoverlay=gpio-shutdown,gpio_pin=13,active_low=1,gpio_pull=up=gpio-shutdown
# led + op gpio-15 en massa
gpio=15=op,dh