can I use bubble tea straws instead of dowels? If yes, for what cake sizes?

I use bubble straws on on make cakes but never more then three layers

I use the straws on all my cakes, even my four tier in my gallery. They are wide so they really support the cake tiers. You can buy them really cheap at any asian market/store. I got a pack of about 50 for $2.

I've used them up to 4 tiers. I have a friend who's used them exclusively for 14 years and done up to a 6 tier cake with them.

Rae