The XLSX LIBNAME engine has a big disadvantage compared with the EXCEL LIBNAME engine: it does not support SAS data set options. This is a showstopper for many Excel files, where the type of data (character or numeric) can be anarchic. The only way I have found to read Excel files reliably is to define the type of every column with the DBSASTYPE= dataset option.

This prompts the question: When does SAS plan to allow data set options with the XLSX LIBNAME engine?

Documentation: https://documentation.sas.com/?docsetId=acpcref&docsetTarget=p09nufzflnat5fn1f92yv8vuiutl.htm&docsetVersion=9.4&locale=en