The first changeover Id go short, maybe 3-5k. Then swap it. The next fill will be more or less 100% of the oil you want, will have done any cleaning that was going to occur, and then you can start taking up the mileage.
Id use UOA to see when your TBN drops, if you have any oxidation/shearing issues, etc.
I've run several 2000 oil changes with good conventional oil to make sure engine Is clean. Does that make a difference? If not that's fine just curious. When I pulled valve cover it was pretty clean. No real build up had a light coating of stuff in the corners that was it and I've about 4 oil changes since then
M1HM is good stuff, if your car burns enough oil you can just top off as addy suggested. My 96 SL2 did not burn enough for me to only top off, probably burned 1-2 quarts between changes, so I actually changed the oil and filter at normal intervals.
More than 2 quarts between oil changes(more than 1 quart per 2,000 miles), then a filter change at 5,000 and top-off; drive until 10,000 with adding another 2 quarts from loss is essentially 4-5 new quarts(or a 2nd oil change without having to pull the plug but once every 10,000).
Filters every 5,000(get a PureONE or Classic etc; unless you want a high-end???). Replace amount of oil lost with filter change.