OP's bike has a 12x148 thru axle (TA). AFAIK, only OMM makes a compatible rear rack, which must be attached to dropouts by a third party (Robert AP) custom TA adapted for the rack (similar RAP TA required for trailer too).

The Tubus adaptor designed for 10x135 QR is incompatible with the Santa Cruz Chameleon. Additionally the rack needs clearance for 3" tires, which none of the Tubus (with the exception of Fat) can provide.

The idea suggested in #8 probably would not work because using the swinger dropout pivot bolt to mount a rack would locate rack (and bags) higher and further forward by ~40mm on a bike with 415mm chainstays. Heelstrike seems likely in this scenario.