Why say only has 91/135 experience? Before I was hired at my current 121 job I had 91/135 and 121. I can tell you that my former 121 "experience" was degrading whatever skills I had. Think about it. In part 121 you have very little flight planning to do and full automation, at least I did, 737,767 etc. And you must ask mommy and daddy before you do anything. Sometimes even go over 3 months without landing.

What ever little skills I had to pass a sim ride came from my 91/135 background of having to do everything yourself and little automation, circling approaches at night to unfamiliar airports etc. etc.

Now that I am back again in the 121 world for the last couple of years I can tell you I am not the pilot I was when I was flying around the world 91/135 in crappy airplanes. If I get furloughed I might have to take some flying lessons to get my next job.