Well, depends on how much that "compatibility" is worth to you. I'm using Dark Speedwork's hack of removing one cog and it works fine. It's not worth it for me to sell my 10 speed rear Zipp wheel at a big loss in order to save less than a minute when I install it for a race to adjust the limit screw to lock out the last click, given I keep a dedicated freewheel on that wheel. It's quick, no big deal. I get the same range of usable gears with this setup in the big chainring with an 11-25 as I would with an 11 speed 11-28, and for most races that's what I care most about. For the occasional race where the lowest gear is more important, I just suck it up, put on a bigger cassette and accept I am losing a middle cog, not worth it to me to spend a lot of money for those rare races.

And that's great that approach works for you, but lets get real...
Slowtwitch represents a tiny portion of the triathlete population. How many triathletes have heard of the dark speed works method??? And even if we just look at slowtwitchers, how many actually work on their own bikes, and how many of those folks have read the threads about this workaround, and how many of -those- actually want to do it?

I shit you not, most triathletes I know likely do not even have a clue as to whether their bikes are 10 speed or 11, and have no idea how to do the most basic adjustments on their bikes, literally. Brakes pads need to be adjusted, saddle height? saddle tilt? index shifting adjustment? etc all those things are trips to the LBS for most these folks. They ain't gonna be doing a dark speed works custom!! :)

I shaved 1.8mm off the rear of the 11 spd cogs to fit my 10spd wheelsets.

I just switched to 11sp on my tri-bike and just bought a Lasko modified 11-28 Ultegra cassette for my 10sp HED Stinger disc. Works perfectly no issues at all, I highly recommend. Easy modification to do if you have access to a machine shop.

I recently had this done to an 11 speed cassette to fit on a 2006 Zipp 182 10 speed hub.

It worked perfectly with no derailleur adjustments.

Yeah I've got a couple of options with my Zipp disc and PX 90mm, but am happy to keep them 10 speed. I don't see the need for 11 speed.

Yeah I didn't either until I got an E-tap, no looking back now!

Lasko sent me 2x modified cassettes a couple months ago. They both work fine on my 90's Zipp that probably was 8spd. I'll got a pair of flat-lander cassettes, so I'll be buying a couple more cassettes from Lasko in the coming year in order to better accommodate out-of-region hilly events.

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