Securing Chimney Base Plate

[madmax224]

Hey everyone. I need some help with a Duravent baseplate. Our plan is to drill holes into the bricks at the top of vent transition and mortar bolts into it to hold the baseplate. We don't plan on tightening it down just give it some lateral support. Once the bolts are in and the mortar dries put down a thin layer of mortar, place the base plate into the mortar and over the bolts, then mortar over the flange plate and bolt it down lightly. I've seen others use notched bricks mortared over the flange and also using pieces of insulating blanket in between the base plate and bricks to give some cusion for expansion or movement but haven't found any info on how well they work afterwards. Has anyone had any problems or suggestions on the best way to do this?