The acrylic case in the T4 set turns out to be same as the case for the T3PLUS. But despite that the dimensions of the two boards are the same, the SoC in the T4 is located at a different place. So, it'd be better if the top plate of the case is modified accordingly (holes shifted).

By the way, the 4 larger holes of the top plate are for a fan, aren't they? But aren't the smaller holes a too big obstacle for the air that the fan blows? Have you compared the temperatures of the SoC without and with a fan, for example the quiet Noctua NF-A4x10 5V fan?