I played a bit today to experiment and it seems blast notes are likely to become the most popular default choice for those who don't care to learn to rely on pinball. For many players, and all players competing for 1st place, blast notes come with a randomized and predetermined bonus amount the moment the game generates the song's note chart. Most differences in scores are now likely to result from a combination of an overdrive power-up and replaying until at least a few blast notes align with unison phrases. This will be incredibly frustrating for songs with checkpoints that require a blast note to get necessary multipliers, and will likely result in burning blitz coins on far more restarts.
With flame notes it was possible for reasonable skill to overcome unlucky spawns, and I very rarely restarted knowing that I could always take a higher risk on the next jackpot to potentially recover from prior loss. That's in fact how I play the game and continue to improve, I only take (what I consider) high risk after botching a run. As a result it's always fun finishing out the song while testing my skill and sometimes improving in score.
There were still songs that lent themselves toward other power-up loadouts, such as fast-tempo songs where OD drains too fast for jackpot to be worthy, overall dense songs across all parts or with many unisons where the benefit of more frequent area-of-effect bursts outweigh what's been achieved so far with flames. If we could somehow look at theoretical optimal scores, pinball/sync and jackpot/flame would almost always be at the top and far beyond any 1st place score that exists today. But I don't think it's the right decision to balance the upper end of the curves at the expense of fun for many and a lot of the competition that existed beneath that point.
The community will keep getting better as long as there's room to improve, and there just happens to be a lot of room for improvement with flames and pinball. There's no way around that without a software patch to change those mechanics. If tournaments were the primary focal point then I stand by my suggestion to use 5-lane songs where overall skill is most likely to determine the outcome and power-up diversity is most likely.
I don't think it's possible to "bump things up" after establishing a better ratio with this nerf and guarantee that existing scores will be attainable. The amount of buffing needed for a fixed value power-up to match top flame scores for certain songs would be far too extreme. The only way to make that guarantee would be to wipe leaderboards (or at least affected combinations that are above every unaffected combination, which would divide and anger some people) or revert this nerf and potentially work on buffs elsewhere.
"Score creep" affecting star outputs is a valid concern but "bumping back up" would have the same result. Also as I've tried to illustrate, given the nature of these uncapped power-ups I think the portion of the scoring curves which overlap the majority weren't really that unbalanced.