The Fitbit Aria scales (older model FB201B) seem to have a design flaw which causes the plastic part in the two front feet to stress fail after a relatively small number of uses (typically just after the warranty expires). Once broken, the scale doesn't detect a zero load causing the display to loop between 'step off' and 'sensing' leading to battery drain. There are no replacement parts, rendering a $120 scale useless for the sake of a 0.10c piece of plastic. It is relatively easy to open and fit this part which corrects that flaw.
Don't know if this part will withstand the test of time any better than the original as of yet. will update anon.
5 months later and PLA still going strong with multiple uses per day. See comments for video of how to open.
Must print with supports. Slic3r gave a good result. Mine printed in PLA, ABS should be fine but does brittle over time.
Gently pry off support and clean flashing