In fact, it doesn’t really make it a lot smaller unless you cut or bend the pins:
The display can be purchased on Amazon for a more expensive price, but I guess then you won’t need to wait for it for a month.
Other than that, the chip is the bulkiest part. It’s the atmega 328 in the DIP package. I believe the vertical size is the same as any other DIP package MCU. If you cut a piece of perfboard in the same size as the display and put both the chip and the display on it, you should have a good idea about the assembled dimensions.
I currently only have a single prototype on a perfboard. It needs at least one tweak. The 4 pins used for connecting to the VESC need to be replaced with a 90 degrees 4 pin JST connector that I will have to order since I’m unable to get it locally. The pins don’t work. The cable keeps sliding off.
I’m going to order professionally manufactured PCBs and put together assembly kits that I can send out to anyone interested for the cost of the parts and shipping. I can send one to you then as well. It will take a while though since I will be ordering from China to keep the costs down. If you’re eager to start designing the enclosure in the meantime, I believe the display is the most critical part to have for that.