Respectfully, Jim, your listed weights don't add up correctly.
PR Total 111 g = 3.91 oz
MR Total 109 g = 3.84 oz = an increase of 2 g = 0.07 oz.
Add in lighter: MR total = 122 g = 4.30 oz, an increase of 10%
PR = 86 g = 3.03 oz
MR = 73 g = 2.57 oz
A decrease of 13 g (the weight of the igniter) or 15%
Add in the lighter and the weights are identical; no change.
I share your awe at the increased case weight. On the surface, it makes no sense. As you say, many folks leave the case at home.
Case weight increased 44%
However, I like the separate Piezo igniter; the darn things seem to have a high failure rate over time. Now I can leave it at home. I always carry a BIB and matches anyway.
So on the surface, there appears to be little or no weight savings for the added cost. Testing will reveal if there is any practical improvement (i.e. the stronger pot supports). 'Twill be interesting to see the effect of the smaller wind deflector and any change in the CO emmissions.
I look forward to reading your complete review.