Text similarity with sentence embeddings

Question

I'm trying to calculate similarity between texts with various lengths. My current approach is following:

1. Using Universal Sentence Encoder, I convert text to a set of vectors.
2. I average these vectors to create the final feature vector.
3. I compare feature vectors using cosine similarity.

This gives me pretty good results for texts with roughly same sizes, but I was wondering if there is a better approach for the step #2 if texts have different lengths.