Not only did Thomas call Jesus God but Lord too. This happened after Jesus was raised from the dead to die no more.I glanced at your study as I have in the past. First, John 1:1c cannot ever be translated as “a god” because Yahweh repeatedly states and it is repeatedly stated throughout Scripture, that there is only one God and there is no such thing as a god.
Second, just a cursory check and the second point in your study—“The next point is that when John (and Matthew, Mark, and Luke also) clearly meant “God” when writing theos (the form of the Greek word which ends in ς), he always used the definite article (‘the’ in English - ho in Greek): ho theos”—is wrong. In John 8:54, John uses theos without the article, and if there is one instance, there could be more. I believe I have pointed this out to you before and yet you still haven’t changed it.
Third, John rights that in Thomas’s exclamation to Jesus, he uses ho theos. So, you should at least be consistent and acknowledge that Thomas called Jesus his God.
This is no different than the Angel of the Lord being call both LORD and God. God name was in him. He was sent to represent God to man. He was not the only true God and neither is Jesus who has now been exalted above all the angels and now carries the name of God. God’s name is in him.