There is no point in continuing this any further
There was no endpoint to Nux's improvement, it is just that the progress he makes slows down so much that it becomes impractical to train a certain skill any longer.
Nux, Vyriana, and Faustina all stared at each other in silence. On one side, they were tempted to spend 5 more years, trying to push the Skill and reach the threshold, and on the other side, they wanted to try something else.
Spending 5 more years would give them a more accurate answer to their questions.
The only two results from it would be Nux reaching the threshold and not reaching it.
If he reached it, it would be a good thing and then they could push forward to the Assimilation Stage and if they do not reach it, then the certainty of their claim of there being no threshold would strengthen even further, giving them more assurance in their future actions.
Honestly, thinking about the two results, spending 5 more years felt like a much better option, however,