I've noticed the same behaviour in my other apps as well (in my Pacer app I even got an out of memory error on the fenix3, because I programmed up until the edge of what was possible with peaks in 2.2.6 up until 15.8k)
you can say that 200-300 bytes more memory consumption is not a lot, but in the tight memory limits the apps have to operate it would be preferrable that new iterations of the SDK use the same (or less) memory than previous iterations.

upper line = screenshot after starting the app
lower line = screenshot after simulating data and pressing start
edit: could be a fitcontributor thing, a freshly generated simpledatafield does not require more memory, but for instance the sample app "MoxyField" establishes the same behaviour of requiring more peak memory in the new sdk