NodeJS MySQL ORM with composite primary keys and specific VARCHAR lengths

I've been looking for a MySQL ORM for Node. I've looked into persist.js, sequelize, and node-orm. Unfortunately none of them support two features that I require: 1. support for composite primary keys (most only support the "id" field as the primary key) 2. the ability to specify my VARCHAR length

I have a table with millions of rows that uses a VARCHAR(16). Upping that to 255 will add hundreds of MB of wasted space to the db. That table will continue to grow too, further contributing to the waste.

Are there any alternatives out there that I'm missing?