If you gas MDMA in DCM you won't get full recovery of your product, I suspect the same is true for Chloroform: Post 439196 (https://www.thevespiary.org/talk/index.php?topic=10937.msg43919600#msg43919600)
(Rhodium: "Gassing in DCM works for MDA but not MDMA", Newbee Forum)
Also, if you use chloroform instead of DCM for the modified performic, make sure you have the reaction flask in an ice-bath to prevent the temperature from going too hot - the bp of DCM at ~40°C keeps the reaction mixture stable at that temp, while as chloroform does not boil until ~62°C, you need to use external cooling for the reaction to stay at 40°C or below - something that needs to be done to minimize the formation of byproducts resulting from thermal decompostion of intermediates.