The term "Akashic records" was first used by Theosophists in the 1800s. The word itself was created from the Sanskrit "akasha", but that in and of itself does not mean that it's origin lies in any Sanskrit literature.
Philosophically it is entirely reasonable to assume that the thoughts of every being are imprinted onto the fabric of our Universe in the realm of the citta. The same thing happens to our subtle body as the four functions of the mind (manas, citta, ahankara and buddhi) interact to create what we perceive as consciousness. So, universally speaking, the same must happen.
But this does not mean that there are "keepers" of these records and all of the other things that go along with it. Those assumptions are not stipulated in any shastra, so they are merely speculations. Of course one could access the thoughts of others through this medium, but one must be careful to simply equate this faculty with the "Akashic records".
An important point to mention is that the Upanishads are "heard" (sruti) by those who are qualified (and subsequently passed on). But this "sound" is part of the fabric of the Universe itself, and isn't due to the thoughts of (deceased) living entities.
As for your example...
"One recent example is , pandit subbaraya shastri , who accessed portions of vaimanika shastra( written by sage Bharadvaja) "
The argument can be made that this knowledge was "encoded" within the very Universe at its creation, or subsequently by a Deva, and then accessed by someone who was qualified. Another possibility is that it was received directly from another living entity. No need for (man made) Akashic records.
A clear distinction between "encoded into the fabric of the Universe" and "recorded thoughts of living entities" must thus be made. As all of us will hopefully attest, many of the thoughts of living entities are quite useless.
One could therefore make another strong argument that "everything" isn't stored, as this would result in a lot of "noise" which would drown out the useful information or higher knowledge.
The point was made that all actions are recorded by Yamaraja. Obviously someone has to take care of the administrative aspect of karma. Only novice (and mostly Western) students of Hinduism are so naive as to think that matter moves itself. But does that have anything to do with the Akashic records? In truth, not at all.
So go back to what the Akashic records are proposed to be, "records of the past and future of human thought and action".
I've given a long reply to your question, because I believe the this is yet another case of modern speculation being equated with the knowledge received from the ancients. It's a dangerous game to play.