Thanks for the answer!
I am happy to hear the hiatus is not permanent and that there's a chance you'll resume work on it! It's not easy to make money and finance game development with shmups as they are relatively niche and pretty much a genre where the best games are made due to passion for that kind of game. It makes sense that you are using other means to raise some money before potentially getting back to this game.
I can absolutely understand the reason you would want to keep the bonus rounds as they are right now, with the same boss fought twice, and I absolutely feel tense and excited when fighting that tougher version of the boss without getting hit at all. The main concern I could have is about length. If bonus stages are shorter, that's one less issue, but having to re-do a 3-minute long final boss with much faster patterns and no right to take damage seems nerve-wracking, and maybe a bit too punishing when you aren't entirely familiar with the game's patterns yet. If all stages have the same kind of pacing as the demo stage, I don't think it is an issue, but for a last boss or a TLB, it might be somewhat different. Though as you said, with less health it could fix the problem entirely too! Well, that's something you'll test and adjust yourself during future developement.
Following your comment, I have just uploaded my current best run here :
I got hit once during a bonus round, but managed to clear the rest of the game without getting hit, so the score shouldn't be too bad.
And thanks for the Super DynoStory offer, but Metroidvanias are a genre I play a lot more casually than shmups so I know I wouldn't be able to comment on it with as much analytical depth as Celestial Crusaders, nor would I be able to invest as much time on it.
By the way, if/when the dev team resumes work on Celestial Crusaders later on, feel free to inform me!