For 1" carbon steerers the usual recommended maximum spacer stack under the stem is about 25 mm. For a 1-1/8" carbon steerer, the most common maximum spacer recommendation is 40 mm but Easton permits 50 mm. You are well within these limits. As noted, what's above the stem is meaningless from a structural standpoint. It just looks odd if it's tall.

The expansion plug isn't needed to support the stem, it just acts as a anchor for the adjusting bolt in most cases.