For those using MicroOS or transactional updates, I had forgotten to mention that install-cli.sh will fail to detect systemd because the directory that it checks does not exist in the transactional-update shell.  I made this change to install-cli.sh:
Shared folders are not working because install-cli.sh does not setup the prlfsmountd service, but it is easy enough to make a service file to start. With transactional updates, prlfsmountd will also fail starting because it tries to mount under /media or /mnt, which is not possible with a read-only root.  This patch mounts under /run/media instead:
	Code:
	--- tools/prlfsmountd.sh.orig    2021-07-19 21:06:09.163988070 +0800
+++ tools/prlfsmountd.sh    2021-07-19 21:05:13.603988839 +0800
@@ -35,7 +35,13 @@
     fi
 fi
 
-[ -d "/media" ] && MNT_PT=/media/psf || MNT_PT=/mnt/psf
+if [ -d "/run/media" ]; then
+    MNT_PT=/run/media/psf
+elif [ -d "/media" ]; then
+    MNT_PT=/media/psf
+else
+    MNT_PT=/mnt/psf
+fi
 
 # remove all obsolete mount points in MNT_PT dir
 rmdir "$MNT_PT"/* 2>/dev/null
 I am also seeing a ~2 minute hang on start while Parallels Tools installer tries to run and fails because it is modifying the root partition outside of a transactional-update shell.  I haven't tried to fix this yet.