My hypothetical assumes that the team was writing 95% accessible software already. The last 2 weeks are for the final push.

Of course, if this is a truly all-or-nothing thing where you need to do it 100% perfectly to incur no extra cost, then that strengthens my argument for the compatibility layer, it doesn't diminish it. Very few non-specialists can get something 100% right on the first shot.

Fair enough.

> Very few non-specialists can get something 100% right on the first shot.

But that certainly doesn’t stop managers from assuming 100%, first shot.

In my experience, a realistic plan can save huge amounts of cost; in far more areas than just accessibility.

Also in my experience: realistic plans are unicorns.