Perspective screen display can lead to problems when placing large or multiple parts. When manually arranging parts which crowd the print boundary the perspective views distort the part edge locations. This is especially a problem with the way S3D handles Delta printers in that the displayed bed surface is NOT the actual bed dimensions (really dumb IMO). The parts should display orthographically - parts layout is an engineering exercise not an architectural presentation. S3D might consider us Delta fools when designing their GUI. At least display a print limit circle on the bed - an easy enhancement guys.