engine facing aft with saildrive installation
Both Volvo and Yanmar make reverse saildrives. There is nothing inherently wrong with reversing the leg so it faces aft when installed ahead of the engine. That said, all the usual issues of engine installations and saildrives apply. One is access, much normal maintenance activities take place at the front of the engine, can you get to what you need? If you like the handling in a test drive, have adequate access to necessary areas, and are willing to accept the normal saildrive issues (watch the zincs closely), there should be no reason to avoid this setup.