I begin 3D printing the bottom part of the case and below is my third attempt print.

The idea is the PCB should clip into the notches shown below.

Another angle of the bottom case.

Yet another angle of the part.

Fitting in the assembled PCB.

Another different angle of fitting the PCB.

Below is when the it completely clipped in.

Notice that USB connector is too recessed and might require moving the connector more outwards.

The connector is still pluggable and charges without issue.

Now testing output ripple and report back.

Lastly, noticed that the PCB is able to move around a bit and will need to look into improving the fit.