i’ve always thought the cloud is incredibly slow - especially at flashing.
what spec machine are you using? it could be because you’re using a mac and an old dfu-util.
on my pretty low spec linux laptop it takes 29secs to compile the entire firmware (from a “make clean”) and flash via dfu - that’s 17secs to compile locally and 12secs to flash via dfu-util 0.8.
if i change the program, then it recompiles in under a second, and that’s using libraries too. i guess ccache helps a bit there too - it makes a massive difference when building android.
if you think the cloud is faster then i suspect the cloud already has the firmware compiled and cached and just rebuilds your “sketch”, in which case it should take under 13secs to build and flash.
i don’t think my higher spec desktop does the flashing any faster than the laptop, but obviously more ram/cpu/ssd helps with compiling.