Customising SharePoint Online Surveys

Hi

I have been asked build a sort of self service regulatory compliance survey on Office 365 / SharePoint Online

When I start to look at the options, starting with no-code :  

1. SharePoint Survey App
2. Excel Survey
3. PowerApps
4. Add-in
5. Nintex Forms

Now option 1 is quite close to what I want when adding  page breaks, and or branch logic .   However,  I really want to customise the basic layout: wrapping text ( see image)  ,  and alternate question shading.  helpful hints in a smaller font etc.

Anbody done this with display templates or JS injection? Also I was quite impressed with the latest PnP / Office Dev Survey so any hints on how that was built would be good.