Why not both?
Tradeshow exhibit design is a niche profession and good to great designers are almost always in demand. One angle you could play is to find a job at a exhibit house that serves the types of industries that you want to get an ID job in. That way you could get some experience designing experiential marketing for those industries and no doubt network with them at the same time.
Some exhibit houses have narrower focuses, or specialize, in serving different types of industries like medical, consumer retail, automotive, etc. Maybe you could find one of these that serves an industry you’re interested in, likely you can tell just by their portfolios. Moving to a company for ID work you would have a compelling selling point in that you can contribute to marketing with your tradeshow knowledge 
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