Never much cared for this design, but you're doing a great job at reproducing it!
It isn't the most graceful looking thing, but I do find it somewhat interesting. I rationalize it by imagining it's not a standard type of Starfleet design, that it's something Starfleet contracted from another Federation agency. It could be a design used more for other scientific or mining or resources agencies and Starfleet contracted a version adapted for their needs. I'd say the same could apply to all three TAS designs.
I actually rather like the general look of the way it is now with some of the sharper lines on it, but the original design had the side support struts merging more smoothly into the main body as well as the viewport bulkhead merging more smoothly into the upper bow so I'm presently trying to make that happen.