This is a pretty strange model. Seems somehow "imprecise built". There are small "steps" and indentations which , if i guess, should not be there.
the image shows the opposite side. Should these faces and indentations be there ?
Note, not all of these mysterious faces are highlighted in this image.
Another example of the "imprecision" ? There is a small step /face, the height difference is 0.022882471
- Due to these small faces, cleaning / deleting faces is more difficult than desired.
Apart from this, using the delete face is in principle "select all
connected faces that should be deleted in one go, the surrounding faces must be able to re-trim/ heal the void from the deleted faces. BUT, the Delete face feature will never deform the surrounding faces , only re-trim.
The 0.0229 example is therefore difficult to handle because the neighbor blend is tangent to a lower level face. Deleting the 0.0229 face would create a new edge beyond that blend.
Regards, Tomas