I have used static mounts for years for media files with good results since we want them highly available. However we have a dedicated HTPC/MediaServer runinning 24/7 (it takes backups at night from the destops too). I've thought AutoFS seemed complicated vs just mounting the server partitons in fstab and letting them run. I don't like switching harddisks off and on.
I wonder why your mounts are behaving like this? is something odd about how you've setup your nfs4 mounts? I think I fixed a similar problem with the 'crossmnt' option on the parent directory in the /etc/exports entry. The child mounts would be delayed for a while after I opened the parent export folder. I think with the crossmnt option on the top level /etc/export entry; the child mounts popped up quickly but it has been a while since I solved that issue.
Listing your /etc/exports would help.
On the client side:
$cat /proc/mounts | grep nfs4
will show all the client nfs4 mount options you are ending up with.
This from might help you from nfs - fstab format and options for the nfs file systems
bg / fg Determines how the mount(8) command behaves if an
attempt to mount an export fails. The fg option causes
mount(8) to exit with an error status if any part of the
mount request times out or fails outright. This is
called a "foreground" mount, and is the default behavior
if neither the fg nor bg mount option is specified.
If the bg option is specified, a timeout or failure
causes the mount(8) command to fork a child which
continues to attempt to mount the export. The parent
immediately returns with a zero exit code. This is
known as a "background" mount.
If the local mount point directory is missing, the
mount(8) command acts as if the mount request timed out.
This permits nested NFS mounts specified in /etc/fstab
to proceed in any order during system initialization,
even if some NFS servers are not yet available.
Alternatively these issues can be addressed using an
automounter (refer to automount(8) for details).