If you install this, it should be fine, but it has not been tested by me personally since this was written over 18 months ago. If you try it, I recommend doing so on a test board and report back any errors. If we consider it to be stable, I'll release it for free in the Resource Manager at some point (with any enhancements needed to bring it up to XF 1.4 speed).
I have tested and find 2 bug
Fistly when you try to "change your vote" after voting, it will show you unrendered BBCODE and when you vote again it is rendered again and it seems ok. But when you try to change your vote again it broken again.
And second bug is ; I saw that you changed response field's varchar value to 400 in poll_response table. But text input area's maxlenght is still 100 in the poll editt form. It must be change.