any large inode size benefits? (ext4)

Larger inode size can help performance for very large files/dirs at the expense of disk usage (and possibly performance for small files).

The bytes-per-inode ratio is what you want to take a closer look at if you feel your inode usage is too high. Many related Q&As on several StackExchange sites.

Larger inodes are useful if you have many files with a large amount of metadata. The smallest inode size has room for classical metadata: permissions, timestamps, etc., as well as the address of a few blocks for regular files, or the target of short symbolic links. Larger inodes can store extended attributes such as access control lists and SELinux contexts. If there is not enough room for the extended attributes in the inode, they have to be stored in a separate block, which makes opening the file or reading its metadata slower.

Hence you should use a larger inode size if you're planning on having large amounts of extended attributes such as complex ACLs, or if you're using SELinux. SELinux is the primary motivation for larger inodes.