**Update** Received some clarification on using the sim time
ATP-CTP curriculum for Sim time calls for, "10 hours of simulator training – intended to prepare the applicant to operate safely in those operations which require an ATP. Of the 10 hours of simulator training, six (6) hours must be completed in a Level C or higher full flight simulator"
ATP Part 61: Will need at least 40-44 hours ME (10hrs@L3 CTP/12hrs@RPA CTP)
R-ATP Part 141: They (FAA too I think) feels that adequate and quality training has occurred therefore they are ok with 141 hires of 25 ME and allowing the completion of 25ME time in the sims.