I just slogged my way through almost 3 months of posts. I mildly regret doing that now, but still have no regrets staying away from this thread during the craziness and staying the course.
As
Okenba pointed out at the time, this gap closes quite quickly based on the total holdings/AUM.
To use the same example of $800/mth, buying IWDA through SCB quarterly is currently about $99.40 for the year (ignoring opportunity cost) and $131.40 (with quarterly batching opportunity cost).
For that same $800/mth, buying VT through FSMOne RSP monthly starting from zero is $47.16 in year one, $74.38 in year two, $101.59 in year three, $128.81 in year four, and it only goes up from there as the total holdings increase. This includes the forex and brokerage, gains from lower TER, loss of 15% of the dividends at 2.69% dividend yield, and the FSMOne dividend handling fee every quarter.
(This is just a quick back-of-the-excel-sheet calculation. For simplicity, I'm assuming the dividends don't get reinvested, and the ETF has exactly 0% growth each year. That's unlikely to be the case, the total holdings hopefully will grow on average, so this naive estimate should be understating the VT case. I also have not attempted to price in the cost of additional life insurance to address estate duty

but it would be less with a lower dividend yield.)
Buying VT just doesn't look like a very good choice in the long run.