Bad idea. They keep the carb jets in tune with friction against the black rubber boot.
do me a favor and pull your plug after running for a day or two. Something is awry here. It definitely would not be the first saw that needed a carb adjusted beyond the limiter tabs, but at the same time, going into that range should be done so cautiously. As mentioned above, the concern is running too lean. That is the fastest and easiest way to ruin a good engine, it's also the most common reason engines die. But long term running too rich has it's own problems and can certainly ruin a good engine when carbon builds up.
Not to worry, really. Likely it was his L jet, not the H jet that was the problem for stalling. It may have also been the L/A setting. I have seen this kind of stuff happening on a LOT of Stihl saws I have owned, tuned and/or 'permanently adjusted' for others. The limiter tabs keep saws from being tuned richer, not leaner. If he trims the tabs and turns the jets out too far, it will be on the rich side, not to the lean. That is by design, as the EPA wants leaner, not richer running saws. So they mandated the tabs. You the sawyer and saw owner want a richer running saw (not overly rich, just richer than "EPA-lean"), and in order to do that you have to trim the limiter tabs. If you follow the methods I have listed above with a good tach, you will not run too rich or too lean. You can always pull and read the plug as I recommended above, after a good long pull on the wood at WOT.
I would argue that engines running lean are the distant second most common reason why 2-stroke saws die. The most common is straight gassing them (by far).
As for carb tuning saws in general, lean running will certainly overheat your saw engine and it will fry in time, or even in a hurry, depending. Running too rich will gunk it up with carbon. Use good gas and 100% synthetic FC/FD rated premix oil and the carbon buildup will likely not be a problem. There are many ways to run a saw too lean (or too rich) after a perfect carb tune and not know that you are doing it. One is to tune your saw with a clogged up air filter or muffler screen and then clean them after you have tuned the saw. That will allow more air flow and result in running them leaner than intended. Another way to run your saws lean is to let them run out of gas all the time. For a minute or so at the end of a tank of gas, there will be less gas available as it sloshes around in the tank and the saw will run at higher RPM. For that reason I like clear gas tanks so I can fill the saw before it gets to that point. It is subtle, but over time doing that all the time can damage an engine. You also want to tune your saw with the bar and chain that you will be running. If you put on a longer bar you need to re-tune your saw, as it will likely run at a lower RPM at WOT with the added friction. That is not a bad thing, per se, but if you do the opposite and put on a shorter bar, you need to retune the saw to keep it from over-revving. Another reason I have seen saws run lean is if they are tuned at a higher elevation and then used at a lower elevation. That is actually pretty common around here where I am in the Cascades. More air at lower elevation means running leaner. Tuning at a lower elevation and running it higher will cause it to run rich. We are talking over 1,000 ft change in elevation here. There is about a 3% drop in O2 per 1,000 ft of elevation. That can be significant if you tune your saw in Portland (200 ft) and cut wood up around Government Camp (at 4,000 ft). Lastly I noticed that when I flipped from Castrol FB premix oil to Mobil 1 and later to Elf 100% synthetic oil my WOT revs went up in my saws. I had to retune them when I changed over. More subtle stuff, but it happens.