Friend of ours needed to have a little extension with downstairs loo and washing machine a couple of years ago, done with two separate saniflo's (probably just about justifiably).
Just got called to look at a leak on the discharge side from the loo. For those not familiar, you normally plumb these using solvent weld with just one (strong) demountable joint to the unit. Plumber chose to insert a universal compression elbow between the S/W (which, to be fair, was secure) and the male outlet from the unit, with acrylic caulk filling the clearance since the geometry didn't permit any "grip" on the rubber seal.