Computer lock outs. Unless you're engaged in multigas deco it's a non issue.
A computer will only lock you out if you've blown through your deco. If you're just on back gas and have gone into deco without the gas (or time) to honour the obligation - well it's your own fault.
A computer will lock you out out if it thinks you've blown through your deco. I expect user error accounts for more lock outs than actual omitted deco. Certainly no fun for a user on an expensive multi-day trip.