Hi Taro,
I am learning on electric and I guess acoustic is way harder due to the strings, fretboard size, action height, immediate feedback, dynamics control, etc. I have a few steps to try eliminating it, see if it works on acoustic:
1. slowly work on pressing the individual chord VERY lightly and comfortably (instead of holding it for too long and make fingers/hand painful) and do one chord sweep. Do the each string note check. It doesn't matter if some notes are missing or buzzing. It's a "work-in-progess" to get a light fretting hand touch, clean sweep.
2. once having the chords comfortably played with ease (or you don't really have to wait; can practise both at the same time), work on the transition - ONE stroke per chord, back and forth (e.g. Open C to barre F, then barre F to Open C). It's a little bit like press + play at the same time for C chord --> switch for barre F --> swtich for open C. LIke trials, no need to press super hard and be perfect. Let our body/muscle feel it. It likely won't work on the first few days or even a week. But slowly, I think our brain will wire things for us.
3. Consciously create "gaps" (i.e. lifting our fingers away from the strings) after one chord, so that we don't drag creating finger noise. I felt the lifting takes some skills too, and that we have to practise. Yes, our chords won't sound connected at first. But once we get the lifting and point 1 and 2 above down - merge them altogether - we will have clean, nice transition chords.
4. This point is like what Tomo always suggested: no tempo first, because if we have a metronome or beat, we will unconsciously chase after it and forgot our real purpose.
5. I guess there's also some specific skills on when to change chords to make it sound without interruption and without finger noise but that's way out of my research/league now.
My recent example is playing palm muted power chords (they are way easier by comparison), which were something like the below (shortened to each "bar" for easy read):
x | x | x | ... | x | x
x | x | x | ... | x | 5
x | x | x | ... | 2 | 4
9 | 9 | 6 | ... | 2 | x
7 | 6 | 4 | ... | 0 | 2
x | x | x | ... | x | x
I was lazy between the first 3 bars and didn't lift the finger on 7th fret and then to the 3rd power chord. Then I had much finger noise. I consciously tried the method above; then it's solved. But it took me quite some while. I'm working on the last two transitions above now (got all sorts of problems, buzzing, missed notes, mishit notes, not on time, etc). I bet it's only much harder on acoustic.
Yeah, let's keep practising!
Hugo