Neil Richerby (Lammermuir Pipe Organs) has Chair Larigot and Great Quinte by half-draw from their respective mixtures on his organ at St. Mary's, Haddington, Lothian, about which I have raved before on this forum.
One occasionally finds a soft pedal stop obtained by reduced wind to the Bourdon. Wells-Kennedy added one at Ballywalter Church, Co. Down, some time after the Walker rebuild (to Lord Dunleath's specification) of the Conacher organ there. There are two drawstops, though.
I've mentioned this one before - the Walker at Wivenhoe Church, Essex, had an octopod Swell consisting of Open, Stopped, "Echo Gamba, Lieblich Bass", Voix Celeste and Oboe. In 1971, Cedric Arnold replaced the Gamba and Celeste with a Gemshorn 4' and Mixture II, to the instrument's great advantage (it sounded more like an old Walker than it did originally!). When I gave a concert to mark the organ's 125th birthday in 2010 (having played it a lot for weddings in my teens so the organist - he's still there - could play cricket), I found that an absolutely ravishing celeste could be obtained by half-drawing the Swell Open with the Stopped Diapason. It doesn't work everywhere, but it does here. Our hosts' organ at St. Andrew, Holborn, has an "Undulant" which works on the same principle, but done "scientific".
I had to explain to the lady playing the hand-blown Bevington at Trinity Church, Newfoundland, that it was a bad idea to half draw the stops to make them softer. John Budgen related a similar story to me about an organist in East Anglia, also of the Essex church where they wanted a balanced swell pedal, despite that fact that there was no swell-box.