[Perfectlap]

don't even think about it. Upgrade the IMS with the LN unit. If I need to replace something I always go for the upgrade. Put it this way, if I were in the market for a Boxster and had the choice between one with the upgraded IMS and one without, I'd gladly pay $600 more for not having to deal with the hassle myself. A faulty IMS can go at any momment and I'm not sure you can really properly inspect the factory unit by just looking at it. Replacing it with an original IMS bearing is pointless. Also, Excellence had an issue where they tore apart the oil filter, more like un-rolled it, and pointed out that if there were shavigs the size of cracked pepper or larger it was not a good sign. But if the oil was recently changed that oil filter with the tell tale debris might have gone into the dumpster.

When I had my IMS upgraded I also had the axle boots serviced, the RMS replaced with the Cayenne seal, and decided to replace the flywheel with an OEM unit (I don't like noise of aftermarket units).

p.s.
After a few mods, some autcrossing and some more mods you'll be keeping that car a lot longer than you thought you would. If you sold it you simply would not be able to find a better car without spending more money. While the newer Boxsters have improved reliability and engineering, in my opinion, the higher price does not correlate into an equal increase in driving pleasure on a dollar per dollar basis.
Put it this way, I see no point spending $30K on a second hand Boxster when a $15K Boxster gives you practically the same Porsche roadster experience.
That's just extra money you don't need to spend that will slowly wither away like all depreciating assets. With your rare and excellent luck you have effectively avoided seeing any of your money go to waste.