Product development is all about finding many solutions, analysing and evaluating each of them, and continuing with the best compromise.
Untill basic architecture, front- and rear suspension, components to be integrated and final specifications become really clear, idea's will go from left to right, up and down, and back again.... the "moving target" phenomenon.
It's useless to put too much time in detailling in this phase of the development process...
In this particular low-volume case, I explored welded square tubes, rivetted aluminium sheet metal, round steel tube trellis construction, bended round tubing, and all kinds of hybrid alternatives.
preliminary frame design for the proof-of-concept vehicle
early phase frame concepts