I own several J-frames. Only one of them has the ILS (lock), but that's because that model was only originally offered with
the lock (M&P 340) when it was first released.
When they later made a version of the M&P 340 available without the ILS, I used that as an excuse to buy a second one.
I've fired a lot of rounds through that first 340 with the ILS, including assorted .357 Magnum and assorted standard pressure and +P loads. Never had an issue with the ILS engaging in an unwanted manner since I bought it and started trying to wear it out.
Now that I have 340's with & without the ILS, I've found that more often than not it's still the first one, with the ILS, that I'm using for a range gun and most of my retirement CCW carry usage.
I've seen a fair number of guys bring ILS-equipped J-frames through range quals & practice (some of which I've also handled & fired), and none of them have yet experienced (or reported experiencing) any ILS-related problems.
I've had to do some corrections and repairs on older & newer S&W revolvers for other things at one time or another, though. (It's mostly been the older wheelguns than the newer ones that have required the attentions & repairs.)
Other S&W revolver armorers with whom I've spoken also haven't experienced, or had reported to them, any ILS problems.
Not convinced it's a potential significant "problem".
Sure seems to annoy "purists" & aficionados, though.