1. we are short on viable cosmological models;
2. it is historically the first big bang model;
3. it was developed by a Christian, possibly inspired by the Holy Spirit;
4. the model is very unique and out of the box;
5. it was nearly buried for about half a century, and is now “re-surfacing”;
6. it allows a near-instant creation of all the elements, and at all the right ratios;
7. it has been considered a viable model by Nobel Laureates, Harvard Professors, etc.
8. it predicted that cosmic rays would be high speed atomic nuclei.
9. it predicted cosmic expansion would be accelerating.
Regarding the last point, a quote from Wikipedia: “In 1931, Lemaitre was the first scientist to propose the expansion of the universe was actually accelerating which was confirmed observationally in the 1990s through observations of very distant Type IA supernova with the Hubble Space Telescope.”
I see you are interested in and discussing Lemaître’s cosmology. I assume you are interested in it from the point of view of adapting it to a YEC creation scenario. But I would caution you to consider the following.