I have a Canon printer and previously an HP and it is possible to produce 4 A5 pages on one sheet of paper using duplex printing and selecting Printer properties and selecting booklet. BUT if you go down that line then print a few pages at a time as I had a document that had over 200 pages and pages 105 to 115 went haywire.
I too have the TS8150 but thought that it would be better to cut the A4 in half first and then print with all pages coming out in the correct order rather than print first then cut after and have to manually sort the pages.
You are able to print ALL pages or selected pages and the TS8150 will print those pages in the right order in that page 1 will back onto page 2, page 3 will back onto page 4 and page 5 will back up onto page 6 etc, etc.
Select Printer Properties, - Page Setup, Under "Page Layout" select "Booklet" - right on the end to the right.
Try - Print out a document of just a few pages and see.
I have done many documents in this way and cut them into A5 AFTER printing and use binder to put them together