I'm using an ESP32 in the same D1 mini form-factor which is slightly wider and has a USB-C port.   I needed a little extra space in the bottom case.  The photo shows the original case (with a slightly modified hole for USB-C) for height comparison with this new bottom case.

The ESP32 I used: https://a.co/d/4knDNNw

A little dab of hot glue to hold it in place worked well. 

This bottom case was designed from scratch in Onshape with measurements taken from the original model's step files.

https://cad.onshape.com/documents/9db4f9d922acebf12e3c17dc/w/e4177d802c56200c85a9b6a8/e/47ce268b6cfcb95f5c1ea7d8?renderMode=0&uiState=695a9a20d13f1a0233849ca8