Actually, downgrading for me is VERY easy and just takes a minute, the reason being that I run my own web server.

All I have to do is unzip the old version, and then drag the resulting folder over to the plugins folder on my other iMac where I run my web server.

I just let it overwrite the 4.3.23 folder, and 4.3.20 immediately takes effect.

It doesn’t even involve FTP.