A customer had created this great looking 3D printable case for the Raspberry Pi + LiFePO4wered/Pi3 and shared it with me.  I was very impressed and asked if he wanted to create a case for the LiFePO4wered/Pi+ as well, and he did!  The case design is available on Thingiverse:

He was also nice enough to send me a sample:

As you can see, the case comes with a hole for a fan, which he had included for me as well.  As the LiFePO4wered/Pi+ has pads for the switched 5V output, I used those as power source for the fan:

The result is a nice, solid feeling and compact "computing brick" for having a Pi-on-the-go:

Because of the active cooling, the system stays nice and cool even under high load.  With a Raspberry Pi 3 B+ running with 4 cores at 100% (load average 4.0), the core temperature of the CPU stayed around 62°C!