There's a bug that prevents the OSXFuse implementation of
sshfs from working with many versions of
sshd, including the one used by
dropbear, which is the implementation used by most SSH server apps for Android, including SSHDroid.
My solution to this problem was just to use a different SSH server app which runs the openssh
sshd instead of
dropbear. SSHelper is expressly designed to do this, but I prefer to start up the full-ish linux environment provided by Termux and then run
sshd from that command line. This has the miraculous side effect of providing a fancy linuxy environment when you
ssh in to your phone.
For Termux and possibly also SSHelper, you will need to edit the
sshd_config text file if you want to change certain options. SSHelper's config file lives at
/data/data/com.arachnoid.sshelper/etc/sshd_config; Termux's is at
/data/data/com.termux/files/usr/etc. You'll also have to add your public key to
~/.ssh/authorized_keys if you want to use public key, rather than password, authentication when you log in. The config file is the same as for
openssh under Linux so that documentation applies, more or less.
Also for Termux you'll have to
apt install openssh in order to run