The cast time of his transform is reduced equal to his health %, so at 20% it will be 20% of the length is has when he is at 100%.

As for recount, I like to keep the option to only keep segments for boss fights, so you can go back and see how you did on each boss. And to have the default showing be current fight instead of overall, so you'll see how you did the last fight without any extra clicking.