Part of the issue is that I think some people are seeing it purely in terms of tiers and not ratings.
Taking two identical scenarios where a character vaporizes another character's body, and in one scenario the victim is rated as 700 Gigatons and in the other he is rated as 990 Gigatons.
If we're upscaling solely to the baseline of the next tier then we're saying that both feats grant a power increase of 300 Gigatons and 20 Gigatons simultaneously. Whether the end result of 1 Teraton is more neat or not, we still have to acknowledge we're being inconsistent here.
When you say something like "If you're superior to 999 Gigatons, then you might as well be rated 1 Teraton." to me that is no different than saying "If you're superior to 600 Gigatons, then you might as well be rated 601 Gigatons".
This same topic could be applied for speed too. Do we have any standards for upscaling speed? Assuming we apply the 1.5x method for speed scaling:
1) If you blitz a Mach 667 character, that's within 1.5x of the next tier so you can be rated as Mach 1000.
2) If you blitz a Mach 665 character, that's not within 1.5x of the next tier, so you get rated as "At least Mach 665."
Some of the users here who think upscaling should only be allowed for very near exceptions. So to those users like
@DarkDragonMedeus, what is the limit for when upscaling should be done? And what is the minimum standard required for upscaling? Vaporizing someone?