George: "...but doesn't the split/aero junk has to handle more lines?"
Len: "My understanding was that the SJR used less lines not more..."
Neither generalisation is strictly correct.
There is nothing magic about the split itself which makes the sail any easier or more difficult to set.
In addition to the mast parrels and the sheeting, contiguous (unsplit) sails seem to need extra parrels to hold the sail to its right shape - sometimes these parrels are the "running" type which means they may be "handled" (adjusted) from time to time eg after reefing. Generally speaking, a split sail would be no different.
The Amiina SJR may be a special case, not just any old junk sail with a split in it. With its low yard angle and high balance, and the proportions of the sail which have been carefully calculated, the horizontal forces needed to hold the sail in shape are minimal and none of the normal parrels (standing or running) are necessary. The sail can be made to drape perfectly under the sheeting forces and gravity alone - almost, but not quite.
Not quite, because the other special feature of this rig is that it uses spanned running parrel-downhauls instead of the usual standing mast parrels (either long or short) which used by conventional sails. These running mast parrels undoubtedly also play a small part in getting the sail to drape correctly. On the usual 5-panel version, two of these are needed, and they are adjusted each time the sail is reefed or unreefed. Just a tweak is needed, and it may be done at leisure. But they are "control lines" none the less, and are part of the deal.
I guess we could generalise by saying that both a split sail and a contiguous sail will need extra control lines of one type or another. A badly designed SJR might well require both types.
(PS it might be possible for the aerojunk or some kind of hybrid to do without any extra control lines, where there are "hard" batten parrels, in the form of wishbone battens, or the D-former or "ovals" seen recently eg Serenity (Boat of the Month Sept 2023). I don't know about either of these types from direct experience. Generally however, there is "no such thing as a free lunch").
By the way, George: in addition to the suggestions made by Len regarding mast placement vis a vis sleeping arrangements: it is not unusual for a junk rig to have the mast offset from the centre line. The sail itself is slightly offset anyway. Off-setting the mast by 20 or 30 cm would not affect performance in any measurable way, and may be a solution if the mast appears to close to the "heads" or a berth or a vital companionway.
Along with the range of mast positions fore-and-aft (by considering the range of mast-balance of the rig, from about 10% to 33% depending on the rig) you might also have a little offset athwartships as an extra variable to play with.