Same thing as last time. You can hit max. The reality is that through my small sample of refining equipment up to 5 on and off of this event (average, not counting my level 8s), there's actually no difference in chance to refine up and the "bonus" is just visual. It encourages spending. There is not enough data to confirm this but my anecdote works for me and thus I do not stress about refining during this period. Many others have maxed refines such as you and still not refined up. That alone shows that it is purely a visual thing that has nothing to do with the mechanic.