Fair enough
I like your summary. I seem to recall many threads about this issue over the years, and lots of confusion. So... I just reviewed the last three January AMEX statements where I had some MF expenses, and it seems I earned two SPG points per MF $. This is what I thought, which is why I postulated that perhaps we might end up with four MR points in the future (since we will be earning a base two MR points per $, and this would be double; this is how I got to four points...).
From my AMEX statements (only showing MF expenses and points below):
Jan 2018
MF: $3305
"Points Earned for Eligible Purchases": 3,305
"Total Bonus Points Earned": 10,805
- "Double Starpoints Bonus": 3,305
- "Other Starpoints Bonus": 7,500 <-- I have no idea why I earned this, perhaps some promotion
Jan 2017
MF: $1660
"Points Earned for Eligible Purchases": 1,660
"Total Bonus Points Earned": 1,660
- "Double Starpoints Bonus": 1,660
Jan 2016
MF: $1599
"Points Earned for Eligible Purchases": 1,599
"Total Bonus Points Earned": 1,599
- "Double Starpoints Bonus": 1,599
FYI, I also glanced at my Jan 2014 statement and saw the same 2x points earned on MF expenses. So, there was no change to this benefit when switching from Starwood to Vistana.
I have more in other months but it seems apparent that I only earned two SPG points for each $ spent on MF.
I look forward to having clarity on this issue so we know how the various cards perform when paying MFs.