Hi BobFrog11,
I’m sorry to hear about the experiences you had with two different mattresses. I’m not sure whether either of your mattresses had actual visible impressions or if it was just foam softening but there are some suggestions in post #4 here about mattresses that have developed soft spots or are sagging that may be helpful.
If this has happened with two mattresses then it’s also possible that you are tending towards choosing mattresses that are too close to the edge of the comfort/support range that is too soft for you so that even normal amounts of foam softening would be enough to put you over the edge of the comfort/support range that you would sleep well on (see post #2 here). If this is the case then choosing mattresses that are in a firmer range may be a good idea.
If your Telluride mattress has visible impressions that are deeper than the warranty exclusions then I would certainly talk with Denver Mattress about a warranty exchange.
If the latex they are using is 100% synthetic (it used to be blended Talalay latex) then it’s most likely the continuous pour Dunlop made by Mountaintop foam which would be a durable material and wouldn’t be a weak link in the mattress. You can read more about the many different types and blends of latex in post #6 here and you can also read more about synthetic continuous pour Dunlop latex made by Mountaintop foam in post #2 here but all latex is a durable material relative to other types of foam. You can also ask them if it’s Talalay or Dunlop and if it’s Talalay from Talalay Global then it would be a blend of about 70% synthetic and about 30% natural.
There are some comments about the Bowles Gold Boxtop in posts #10 and #11 here and in post #2 here.
While there aren’t any obvious weak links in the mattress for most people … given your experience with your previous two mattresses I would be very cautious and make sure that this mattress isn’t also “on the edge” of being too soft for you as well because with 1.5" of soft quilting foam and some of the other softer materials in this mattress it’s still possible that even normal foam softening may take you out of the comfort support range that will be suitable for you faster than normal as well although the zoning in the center third may help offset this to some degree.
I read back through your previous posts and I didn’t see anything about your weight or body type but this would be particularly important if you are in a higher weight range.
Phoenix