It no longer appears to be possible to disable biome blending about sodium-fabric

[MeeniMc]

Even when set to 0 it would not produce sharp borders because Sodium, in addition to the biome blending, has color smoothing inside the blocks.
You can refer to my pr #2267, it re-enables setting bleding to 0, and explains what I just said above. Because it doesn't produce sharp boundaries in any case, the difference between 1 and 0 is very subtle.

[muzikbike]

I remember previous versions didn't produce blended boundaries at 0 though.

[ShaneBeee]

I can here to make a suggestion about this, and saw it was already here.
Can confirm, same for me.

I remember a few versions back you could set it to 0 and they were sharp.
I personally use this for testing/debugging custom biome stuff.
Id love to have this option again.