Never had a boom tent. Did have a sun awning, once. Don't know whether or not this will help, but I'll share a few random ideas.....
What you have there may have been designed to fit a particular make & model of boat
The zippers may be for a "door" into the cockpit
? From the front, it looked okay. Another possibility is that the aft end of the awning zips together along the centerline, and will require a spreader at its aft end.
Our old awning had spreaders that went athwartships. Are there pockets for spreaders on your piece of fabric
? We used bungees from grommets on the fabric
to the lifelines
, for downhauls. [we made the spreaders from pvc pipe.]
You have a lot of fabric there, you should be able to modify it to suit your boat, either by adding more fabric if needed, or removing it selectively to adapt to the contours you have to work
with. Do you know what fabric it is made of?
Good luck with it. It will be an interesting project