I have the same problem on a Samsung Note20 (non-ultra). I was thinking of a photoshop "curves" style interface to map pressure to line thickness %, but that is probably overkill.

yes!!!!! we need this function

With the Samsung A Pen on Galaxy tab 3S, pressure sensitive writing is only usable when applying quite some force. Without applying force the lines get to thin and break. By comparison the Samsung notes app handles this much better. Maybe you could add a parameter to calibrate pressure sensitivity to prevent lines from becoming interrupted all the time.

Please implement this. This is a deal breaker for me. Without it, the handwriting looks inconsistent.

Add a user settable level of initial pen input threshold level to prevent odd squiggly lines drawn just before and after touching the screen with an active stylus.

This means that a minimum pressure threshold must be met before the lines start to be drawn on screen. The starting pressure level is then offset by this value to act like a normal pen input, so it doesnt start off as thick

I always use 0.3mm ink with pressure sensitivity enabled.

Sometimes getting to close to the screen with my pen will cause a very light pen mark over some important figure I have drawn. While in the app, this mark is practically unnoticeable, but when you generate a PDF this mark becomes a much thicker and intrusive stoke.
Trying to find and eliminate these accidental stokes is usually difficult.

It seems like you are missing PDF support for marks that are that this minuscule and then are up sizing them on export.