reversed clip output is choppy

I'm putting together a compilation video in regular 1080 HD, using quite a few separate clips. I have converted any 4k clips I am using to 1080p before importing them into the timeline.

I have one particular clip at the end, where I do a dynamic zoom and reversal both at the same time. When I render the video that part of it always stutters a bit. I am rendering in mov wrapper with H264 codec. My hardware should be fine, i7 6 core processor, 16GB ram and I use SSD's for cache and file location, and render to an SSD.

Is the reverse and dynamic zoom at the same time too much? Should I just do one step, export that clip only to file them re import and do the other step?

My compilation is pretty good other than for this last little stutter at the end, any suggestions?


thanks in advance.