On a 32 GB microSD card, it takes about 170 seconds to boot.
Looking at the boot logs, it looks like you are doing an 'fsck' on the entire card, every boot.
This gets real tedious on big cards.
I suspect you are trying to head off corruption problems with the new customers jerking the power on the pocketbones.
[ 4.399012] random: udevadm: uninitialized urandom read (16 bytes read)
[ 4.399106] random: udevadm: uninitialized urandom read (16 bytes read)
[ 4.399827] random: udevadm: uninitialized urandom read (16 bytes read)
[ 4.400464] random: udevadm: uninitialized urandom read (16 bytes read)
[ 4.401123] random: udevadm: uninitialized urandom read (16 bytes read)
[ 4.405921] random: udevadm: uninitialized urandom read (16 bytes read)
[ 4.406825] random: udevadm: uninitialized urandom read (16 bytes read)
[ 6.070942] random: fast init done
{<<<<<<<<<<<<<<< Hangs Here for a minute+ (16 GB microSD card) >>>>>>>>>>>>>>>}
Begin: Loading essential drivers ... done.
Begin: Running /scripts/init-premount ... done.
Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done.
Begin: Running /scripts/local-premount ... done.
Begin: Will now check root file system ... fsck from util-linux 2.29.2
[/sbin/fsck.ext4 (1) -- /dev/mmcblk0p1] fsck.ext4 -a -C0 /dev/mmcblk0p1
rootfs: clean, 76719/1927296 files, 589028/7813760 blocks
done.
[ 89.774723] EXT4-fs (mmcblk0p1): mounted filesystem with ordered data mode. Opts: (null)
done.
Begin: Running /scripts/local-bottom ... done.
Begin: Running /scripts/init-bottom ... done.
[ 90.407599] systemd[1]: System time before build time, advancing clock.
[ 90.511512] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 90.567036] systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN)
[ 90.586224] systemd[1]: Detected architecture arm.