I rotated our Thetford toilet on our TT last year also 45° and was easy to do. Just remove the toilet and remove the screws holding the flange. The flange is screwed to the black tank and turns clockwise to tighten, so if you want to go CC you will be lifting it away from the floor. For me it only moved the flange less than 1/8" and found that the tank had enough play so when I tightened the flange it went to the floor. If not you may need to put a thin washer under the flange at each screw hole. The mod worked great for me, no leaks and solid to the floor.
2006 T23FBL Wildwood Lite
2009 Ford E-350 Super Duty 5.4L 3.73