If I'm not mistaken FlowStudio can export as PDF which can be handled by PostScript printers, if it is printed via VPDF/APDF or other programs that can also print PDFs.

I never had much success with TurboPrint with MorphOS, &/or I was never entirely satsified with the wait for the GS: device to interpret the file, and often I never got any output, but with PostScript/PDF output the results are far quicker, and superior.

Bear in mind that the "Printers" system that was implemented with v3.10 was supplied "incomplete" as the USB device (USBPAR:, which is actually a misnoma, because as far as I am aware you cannot have a Serial (USB)<-> Parallel device - as it's either one or the other) for printing files was not part of the installation with v3.10, probably an oversight, but you can acquire it from the Beta "Printers" archive, and install it manually.

I have advised Zukow of this anomaly in the "Printers" system, and I understand it may well be correctly implemented in the v3.11 release, whenever that is to become available.