I understand the math for CAGR, very, very well. The ideal situation would be to buy your limit of a set at MSRP or better (e.***., heavily discounted) on the day it goes EOL. This shortens the time component in the denominator of a CAGR calculation, increasing the value. This strategy also increases the price differential in the numerator, and also does wonders for the CAGR. Also really, really good for your CAGR would be to sell those sets the next day or week when they experience there first, post-EOL bump. You'll find a CAGR of thousands of percent that way.
The flaw in CAGR is that it is essentially a value over time metric (a derivative, in Calculus terms), not an absolute dollar metric. Derivatives can be tricky and can mislead. I'd rather triple a $200 set in 24 months for $400 profit (e.***. TH) than sell that same TH a week after EOL for $100 profit, even though CAGR is much, much higher in the later case than the former. Why? My time and effort. And the fact we don't have great EOL sets coming available every week, more like a few/year.
I factor in my active time to manage my portfolio (buying, selling, etc). I'd rather obtain sets relatively easily and ban-free (e.***., off Amazon Prime at MSRP with free shipping/no tax) and then just hold long enough that exclusives experience a nice value increase.
Clearly, there's point in the CAGR curve where you'd be better off selling and re-buying the next-to-retire exclusve. To cite a relevant, current example, mathematically, it may be the time to clear out your TH inventory and re-invest in PS. Or perhaps, wait until you think PS is going to retire, then sell-off all your TH and roll it over into PS. Other problems are 1) predicting future value; 2) finding ways to obtain your goal number of sets at MSRP or below, and 3) finding enough buyers quickly when you need to roll-over sets. None of these issues are trivial, even though such strategy maximizes CAGR.
I'm happy with buy and hold, with relatively little hassle on the buy end, and with steady sales on the sell end, via eBay and Craigs list. YMMV.