I can't help you find a "digested text about Giedion and its connection with Einstein as well as the Shinoha's critique." I hear there is a archinect user that goes by the name of Mworld828 that is writing a thesis on this exact topic. Maybe try reaching out to them for some preliminary notes.

The process of digestion is what will create your thesis. Don't run from it.

As you already may have noticed, at the architectural scale wherein we occupy as human beings, space and time are basically a classical (Newtonian) experience. Physically there are parametric 'non-Euclidean' geometry in architecture. But this is different than an intuitive experience of spacetime and all of its non-Euclidean characteristics. In theory, modern physics and architecture are inevitably disconnected.

Nevertheless, Giedion wrote about Cubism and Futurism as examples of how artists and architects responded to relativity in the early-mid 1900s. After all, relativity implies much more for humanity beyond just the realm of physics. Perhaps we can derive from all of our new understanding that the human intuition is limited to a form of consciousness that is unable to perceive space and time as one. So ironically, we are inextricably connected beyond our own understanding. Bringing this wisdom into architecture is a whole another question on its own that challenges the world's ethics, politics, and economics.

I suggest Bernard Tschumi's "The Architectural Paradox."

Many thanks Continuum, your comment was very useful. Will work on it and read my other books I bought.
Cheers

Do kids still read that!...it was written, in 1948...good luck with that one.