Not sure if this helps but...
My old 2000 C2 tip 3.4 had IMS "play" & the engine was replaced (by Porsche) at 30k miles. The car was running fine, but happened to be in at an OPC for a major at the time it was noticed. So, as other folks have mentioned, it's really down to ones attitude to risk & seems to be a bit of a lottery.
Having been around these cars (& their owners) pretty much from the off, I would recommend a 3- 4k slush fund per year (which is sensible on any performance car) or maybe a maintenance plan if anyone is still doing them? If the maintenance plan sounds good, then the provider would do a once over anyway before issuing the insurance. This would then highlight any potential looming issues & the call could be made either way.
Porsche warranties only run for 14 years (the 14th year being the last year in which you can add the car to the plan if I recall correctly).
It's such a shame these cars (as have many other performance cars) have a few Achilles heels as they are brilliant fun to drive vs the air cooled cars I've driven & owned. To be fair though, the air cooled stuff is great, but in a very different way...
I eventually went the 996 Turbo route (the 996 cars really are that good in my opinion!), but still have a soft spot for the n/a 996.1. I love the look too & would consider purchasing again in the future - for what it's worth?
As I say, no idea if this helps or hinders..! But enjoy a truly great drivers car!
Cheers
Mobs