The Tip function certainly will not hurt anything... technically it won't let you do something stupid anyway. There is a certain conflict of interest here, as you ask about swapping a manual transmission in... something that MUST be shifted by you ALL the time, yet you are concerned about using the same availability in the transmission that you already have.
I can tell you that I would almost for sure be in Tip mode all the time if I were towing with any automatic transmission so-equipped, unless it specifically had a tow/haul mode available, or there were some really good load sensitive software in the transmission controller. My Sprinter is actually very good at that, but unfortunately while it has a manual mode it does not allow for you to lock it in its highest gear, like your Passat does.
In my opinion, the CR engines work great with the DSG, probably better than any other engine VAG bolted to them, although they still seem a bit upshift happy. I do not like lugging the engine below 2000 RPMs, and would actually rather run it closer to 2500 RPMs when pulling up a hill especially with a trailer. Tip allows you to do that with ease.