Perhaps you missed this quote from St. Basil the Great regarding those who argue about the shape of the Earth and try to use Scripture to prove it.
St. Basil, Hexaemeron, Homily 9: "Those who have written about the nature of the universe have discussed at length the shape of the earth. If it be spherical or cylindrical, if it resemble a disc and is equally rounded in all parts, or if it has the forth of a winnowing basket and is hollow in the middle; all these conjectures have been suggested by cosmographers, each one upsetting that of his predecessor. It will not lead me to give less importance to the creation of the universe, that the servant of God, Moses, is silent as to shapes; he has not said that the earth is a hundred and eighty thousand furlongs in circuмference; he has not measured into what extent of air its shadow projects itself whilst the sun revolves around it, nor stated how this shadow, casting itself upon the moon, produces eclipses. He has passed over in silence, as useless, all that is unimportant for us. Shall I then prefer foolish wisdom to the oracles of the Holy Spirit? Shall I not rather exalt Him who, not wishing to fill our minds with these vanities, has regulated all the economy of Scripture in view of the edification and the making perfect of our souls? It is this which those seem to me not to have understood, who, giving themselves up to the distorted meaning of allegory, have undertaken to give a majesty of their own invention to Scripture. It is to believe themselves wiser than the Holy Spirit, and to bring forth their own ideas under a pretext of exegesis. Let us hear Scripture as it has been written."
Quote from St. Basil:
"He [Moses] has passed over in silence, as useless, all that is unimportant for us."
I understand what St. Basil is saying. It seems that his view was that we can give too much importance as to the shape of the earth, or eclipses, etc.
There was a time when debating the shape of the earth would not have been needed, but it is needed now, IMO, given what has become of science. I do think that spending a lot of time speculating about the shape of the earth can take away from other things that we should be doing instead. However, St. Basil does not say what he believes the shape of the earth to be. He does say this in chapter four of the Hexaemeron:
...."Heaven, poised like a dome, to quote the words of the prophet; [1523] earth, this immense mass which rests upon itself; the air around it, of a soft and fluid nature, a true and continual nourishment for all who breathe it...[...]."
St. Basil does refer to Heaven as "poised like a dome," and that..."this immense earth which rests upon itself," which to me seems like it refers to a flat plane, though that may be debatable.
Link to chapter four here:
https://www.elpenor.org/basil/hexaemeron.asp?pg=32