I have had some correspondence with someone else who has produced a similar lectionary that takes in the whole of Holy Scripture, but from a slightly different (Lutheran) starting point.
He has made me aware of research on the so-called Ordines Romani, a list of very early, first millenium liturgical instructions for the saying of the Office and the Mass. Those numbered XIII to XV give a fascinating picture of the breviary as it was said in the major basilicas of Rome, staffed by local monastic foundations, back in the early days before St Peter's became a "collegiate" church. St Peter's once had four monasteries to resource its liturgical life.
Somewhat remarkably, there is good evidence that at this early date (we are taking here about the 7th to 8th Centuries) the entirety of Holy Scripture was supposed to be said or sung on an annual basis at Matins - at least notionally - as an ad hoc lectio continua. This very possibly goes back a few centuries more, although there is some evidence that the shift from reading long sections of the Old Testament in an ad hoc fashion at Mass, to doing so at Matins (which previously were most likely constructed of psalmody almost exclusively), may have happened at some point in the 6th or 7th Century.
It seems that the early Roman Breviary's year was divided up into four sections, roughly corresponding to the seasons and bounded by the Ember Days. Genesis to Judges formed the spring lessons (Quinquagesima to Passion Sunday) along with the Easter lessons of Acts, Revelation and the General Epistles. Summer saw the reading of the books of the Kings; and Autumn the Wisdom books. The Prophets from Isaiah to Malachi were begun in December, and continued until the following Lent after the Christmas season. The Gospels and the "Apostle", i.e. the Pauline Epistles, were read at the stational Masses. Thus the early Roman Breviary: which varied somewhat in praxis, from monastic house to monastic house, from one basilica to another, even within Rome.
And then came the cross-fertilisation, or some would call it bastardisation, of the Roman rite with the Gallican, with the introduction of the Roman rite to the court of Pepin and the Franks in 754. This to-ing and fro-ing over the Alps produced many of the classic features of the lessons of the Roman breviary: the seasonal grouping of the lessons was weakened, as the months from August to November took on their recognisable pre-1970 form, and the Pauline epistles made their way into the post-Epiphany period. And the Office as sung at the basilica of St Peter became the liturgical standard, after it became a collegiate church and took over the running of its affiliated monasteries - thus introducing an element of standardisation into the Office at the same time as it was beng Gallicanised.
What I find most interesting, however, besides the above mentioned historical development, something of which I knew next to nothing, is the common feature at this period, which is an assumption that the whole of Scripture was of liturgical value and should form the life and prayer of the church... it is a period which gave us Bede's commentaries on the Tabernacle, and ends with the 12th Century Victorine commentaries on the more "obscure" parts of Genesis. These commentaries were not produced by library scholars poring over books that no-one else ever read, they were (I believe) familiar liturgical texts, heard year upon year, and heard within a Christological and - dare I say it - neoplatonic frame of reference.
I give the internet archive address of one of the books I was directed to:
The History of the Roman Breviary by Pierre Batiffol https://archive.org/details/historyofromanbr00batiiala
The other bits and pieces that I was sent are from more recent books and studies, so I am wary of copyright rules. But this particular summary of the lesson schemata from the Ordines is on-line:
It has encouraged me to know that the norm of reading the entirety of Holy Scripture in the liturgical year is not some kind of supposedly "silly" Protestant, ergo anti-catholic fad (one hears such profoundly un-Patristic sneers about the sacred word from time to time), but is sadly another of its ancient traditions that the Apostolic see has let fall by the wayside.