To make up the games re-instate mini leagues in League Cup, played early season, with those qualifying for Europe given byes into the next round.
Re League Cup, don't need to get too bogged down in arithmetic. Where there's a will there's a way.
Something like 4 euro qualifying clubs byed. Invite 2 clubs from Juniors, Highland League whatever to make numbers up to 40. 8 leagues each with 5 clubs playing home & away. 8 winners go thru plus 4 best runners up. Those 12 clubs are joined by the 4 Euro clubs to make 16 and a straight knock out from there on.
As it is now each SFL club is guaranteed 18 home matches and one split League Cup tie (ignoring the inane Alba Cup). A 16 club league would provide 15 home matches and a sectionalised League Cup (as above) would provide a further minimum of 4 home games.
Also I'd seed the League Cup sections based on league finishing positions the season before. That would have the likely added incentive of mid table teams having something to play for late into the season.