To respond to the advice given in my previous forum post (look at it for context):

1. I've been playing fast maps for months and it has not helped.
2. Finger lock is no longer an issue but I'm still slow.
3. My top plays are all short because longer maps usually have 1 to 2 stream parts where I always break.
4. Yes I've tried ring index. No it didn't work.

Playing fast maps has improved my aim control and burst speed but not my streaming speed.

Not only are your top scores all short and easy farm maps, but you don't seem to be an accuracy player either. I would strongly suggest you to no longer play those maps, as you don't gain any meaningful skills from them. If you keep farming like this in the future, with the sole aim of achieving more pp, you won't get a chance to fully improve your streaming ability.

However, there are many ways to be good at streams! What helps me is to start at a level where I am most comfortable, then work my way up day by day by increasing the bpm. I never miss an opportunity to play a stream map whenever I feel motivated to play the game, which means you have to be consistent enough in order to achieve results, otherwise you will just stagnate. All this combined with the fact that I take breaks when needed, of course!

I usually play maps like these btw beatmapsets/43701 beatmapsets/956519 beatmapsets/198053

First, understand that basic streaming ability is almost entirely about how well you can read streams and your technique.

First, reading wise, make sure each tap of yours is a conscious reaction to a note in the stream, don't just try to set your fingers into 180 bpm streaming mode and then forget about the tapping aspect, focusing solely on flow aim.

Second, technique wise, pay close attention to deficiencies in your technique. As an example, does your middle finger often not press down enough, resulting in a missed tap? Try a bunch of different techniques and try to find one that sticks. For me personally I tap almost entirely by rotating my wrist, especially on higher bpm streams, my fingers themselves don't move very much. You could try this, or you could try keeping your fingers more curled/straight (personally I prefer curled but I imagine many prefer straightened).

same with 1millionx your hours. i have a new theory that you can only deathstream as fast as you can count so if you wouldn't mind being my test subject you start grinding counting right now i'll keep mashing long stream maps and we'll check back with each other in a year

To respond to the advice given in my previous forum post (look at it for context):
1. I've been playing fast maps for months and it has not helped.
2. Finger lock is no longer an issue but I'm still slow. The problem is you're slow, not fingerlock.
3. My top plays are all short because longer maps usually have 1 to 2 stream parts where I always break.
4. Yes I've tried ring index. No it didn't work. I've even seen a Taiko liveplay using pinky finger. Not the issue.
5. Playing fast maps has improved my aim control and burst speed but not my streaming speed.

Information being you're stuck at 140 BPM stream.

For number one and five, how fast? If it's 200 BPM then you're doing yourself very little justice. Get comfy with 140 BPM long streams. If you have, you can play up to 180 BPM short stream (might be different for every player). So the SOP is:
Get comfy with your current BPM long stream > Upgrade > Get comfy > Upgrade
You might be able to upgrade like 20 or 30 BPM for each step? idk

For number 3, 'longer maps usually have 1 to 2 stream parts where I always break.' So basically you play only easy maps for you. Right? How would you improve if you're not even trying. If it's fc-able strive for it, master it, get comfy. There you get: stability, new skill.

-You're afraid of submitting C scores? Use V2
-You on a fluke FCed when on V2 while you can get a lot of pp from it? Look at the leaderboard.. IF someone FCed it then you're just not ready for the FC submission.

Closing words:
I am and old Taiko dog with severely rusted skills. Speed, tech, stability and acc, stamina, all of it. For the last 2 months and after 4 years of hiatus I managed to surpass my best speeds and stamina, but the rest still needs rehab. In my case, I just pick any map that I enjoyed and played often (it being I can possibly FC), then I raised the BPM using osu! BPM changer like from 230 to 300 with 10 BPMs increment each. Then I play it level by level until I got it stable. I got 50 pp for playing fun maps and I didn't even farm for pp. I farmed for acc and stability.