Shell Poor Printability

File `PI4Buper-shell0701.stl` has neither it's top nor bottom completely touching the print surface thus resulting in sections printing in mid-air or require supports

Suggestion would be that it is printed with the top on the print surface, however the Bigtreetech Logo is recessed under the top thus result it printing in mid-air or requiring supports so my suggestion would be to raise the logo so that it is flush with the top thus touching the print bed.

If possible, please also provide the CAD file for the shell like the board itself.