Completely unrepresentative though, since the single 16GB stick is not working dual channel and is hence at half speed. It’s a terrible idea to not mount memory dual channel. You’ll need two 8GB sticks for comparison.
The answer to that seems to be no, not really, not anymore since it’s now optimized to run with 16GB.
OP should note that DDR5 is actually slower with 12th Gen Intels than DDR4 is. If you are going for DDR5 now, then that is only for sake of reusing it with some different system in the future, otherwise you’ll be paying more for less. And future proofing right now (or at least the last I checked DDR5 prices were quite high) might not even make sense.
its a bit unfair compare, or ?.. single vs double-channel
I would pay for the 64GIG RAM… There are so many situations where you can stay much more relaxt if your apps consume bit more memory. ( example: with my 64G , I have a pagefile of 1G, so mostly never slow paging is used ). If you plan doing additional video editing or similar memory intensive stuff, you are again better with 64GIG. The performance of both sticks is similar and you will not realy notice a 400Mhz RAM speed difference.
MSFS specifically will benefit more from the extra 400Mhz (a bit) than it will benefit from the extra 32GB (you most likely won’t gain a single frame). Both would probably lose few frames in comparison to 32GB DDR4 3600Mhz CL16 ($150) due to faster timings on DDR4.
Just for MSFS, 32 GB is completely fine and likely will be for a couple years to come.
If the the $197 dollars saved on ram can be put towards a better GPU, then that’s where your biggest performance gain will come. The extra ram won’t hurt of course, but you will notice no benefit whatsoever.