USB persistent encrypted install (2018.01) gives strange mount point - minor detail

[bpb21]

I've followed the directions to make a live USB, using a 128GB USB drive and the latest (kali-linux-2018.1-amd64.iso) x64 image. (Here: https://docs.kali.org/downloading/ka...ve-usb-install )
I used dd as stated in this how-to, from another linux box, and ended up with a /dev/sdb1 and /dev/sdb2 par***ion. Everything seems to check out ok there.

When I go to follow this guide on making it persistent, I have some trouble. (Here: https://docs.kali.org/downloading/ka...sb-persistence )

This may sound like a total noob mistake, and it may be. Since my drive is 128GB total, I want to use all that space; certainly more than the 7 GB in the tutorial. Plus, I'm just not sure what to do with this code:

end=7gb
read start _ < <(du -bcm kali-linux-2016.2-amd64.iso | tail -1); echo $start
parted /dev/sdb mkpart primary $start $end

Is this significantly different from just using fdisk and adding an sdb3 par***ion, using the remaining available space after a live install to USB? This is where I've diverged from the instructions, as I just use fdisk with the remaining space on the drive to create the /dev/sdb3 par***ion for persistence.

In any event, I finish with the persistence tutorial and I do the luks encryption part so that I end up with a fully working live, persistent, encrypted, USB drive of kali linux.

My issue is this: the mount point for the encrypted par***ion ends up being /lib/live/mount/persistence/sdb3 (physical location being /dev/mapper/sdb3) and that seems like...a handful to type in any time I'm wanting something to persist.

Further, the contents of that directory are: lost+found, persistence.conf, rw, and work (3 directories and the persistence.conf file).

Is this the normal mount point for a persistent par***ion? I can make another directory and/or save files at this level, but anything I save in /lib/live/mount/persistence/sdb3/work/ (for example) is not persistent.

These instructions seem to be for the 2017 images; did anything change in the 2018 image? (That I may not have caught in the release notes.) Is this the normal mount point for persistence?

Sorry if this is thoroughly covered elsewhere. I think I've done my due diligence searching before posting!

Edit: while I'm at it, is there a reason for making an ext3 file system specifically? As in, is there a functional difference from using ext2 or ext4? See this guide for steps: https://docs.kali.org/downloading/ka...sb-persistence

mkfs.ext3 -L persistence /dev/sdb3
e2label /dev/sdb3 persistence