I'm kind of tempted to add a couple of live logging features, but if I start adding stuff like that I'll definitely need to add some styling to avoid confusing people with more advanced features. One option would be an auto-increment on the time field (so once you put in a point it'll advance that to the next 30s and focus the temperature field so there's just one number to put in when it's time).
The other option, which I haven't seen before, would be to have a timer update the time field continuously and raise the temperature value with each insertion so you could just hit the button when the temperature gets to the next value. No typing at all.
The latter seems like the easiest option and would be handy to have at events where there may or may not be a computer hooked up to the roaster at all and if there is it's probably not set up in a way that's convenient for taking your data with you.
And there is such an event coming up in a couple months.