I often see pictures posted of people with loads of weight above their heads but in very compromised positions, both in the press & the Overhead Squat (OHS). A common trend is to hyperextend the upper back and compromise the shoulders. (This only overloads the lower back and hip flexors and stresses out the anterior shoulder muscles).
This can be for various reasons:
Lack of shoulder stability
Lack of thoracic mobility
Lack of pelvic stability
Lack of hip mobility
Lack of knee stability
Lack of ankle mobility
Any one of these things, or a combination, can change the OHS dramatically. Don't sacrifice form for numbers.
Just make sure if this is a movement you do regularly, particularly if it is loaded, that you can tick all the above mentioned criteria prior to load. Or at least be working on your weaknesses and immobilities that are apparent and improving them prior to load.
Nothing wrong with working the dowel rod guys. I don't know about you but I'd rather achieve a perfect or close to perfect dowel rod OHS whilst preventing injury than an ugly weighted one which causes dysfunction in the system.