tl;dr show the first results screen time before the bonus kicks in and add 10 seconds to your submissions lol

So Freeze Rally can go into negatives because collecting all Freezers results in a -10 second bonus.

speedrun.com doesn't allow submitting negative times so the only workaround is to add 10 seconds back to the final time, effectively making it positive again. Obviously, if another run doesn't get the -10 second bonus, you're still going to add 10 seconds to those submissions too. The submissions will stay equal this way.

Now the fun part is observing what the game does when it gives you the -10 second bonus

(Timestamped link)

The final time is shown to be 5.98, therefore with the bonus it should result in a time of -4.02 The game however, turns it into -4.00 instead, effectively adding 0.02 to your time. Then, the screen after all this shows 4.01, a positive value with some mysterious decimals out of the blue.

As far as I'm concerned, only the first value should be considered when submitting runs. This is, the screen with 5.98 in it. You need to use the results screen before the bonus kicks in, because using the final frame of gameplay isn't accurate, the game performs some finish line calculations for your final decimals. After the bonus kicks in, even though is your IGT, it's not capable of performing the math consistently. Most runs on the boards it does fine, but negative times get messy. The post-results screen flips your negative time into positives and adds decimals at random so this one's completely useless.