I bought the Matrice 200 series I am designing mounts for front,back,top and bottom - pic of M200 front with motor arm clamps and MicroSense Rededge adaptor. Should be flight tested mid march. I will be doing bottom next. I like the fact it use some of same components as my I2
With reference to your question on Mavic , the tri mount can be configured with two point swing adaptor. The only issue is payload . I have flown my M3 with a Insta360 on top and lighting under each motor arm no issues . Payload was about 420g I would not exceed 500g if balanced between 3 points on CG .