Thank you for your response mrmikel. I have gone through some of the proposed solutions. Among the ones I have seen I'm closest to
Formatting Poetry for Epub and Small Devices when it comes to breaking lines. Still, a lot of manual work.
I'm not planning on selling anything. I was merely experimenting on this tricky format (to understand the limits). Publishing PDF may be the best way as you point out. When I publish something I prefer to publish both in ePub and in PDF. Maybe poetry should be an exception?