I didnt suggest that you work harder, I know what goes into building custom functions into a site.

I suggested a public Beta testing period. (I would add to that a formal bug/error reporting process and changelog but that's not everyone's thing, depends if you rather deal with individuals or reports from individuals)

Utilise your users as your testing base, slip them a few free DVC bids as thanks and keep the whole thing in testing until you know it's good to go.

imagine the drama involved if this timer was to have an error just as that mining rig gets to 0...I dont believe the crypto community is forgiving enough to accept those kinds of mistakes.