In those cases, it may be easier to use wickedpdf.

on the iphone, you should be able to hook it up to a mac via the lightning cable and open up the safari debugger. This would give you the ability to see any console errors in the iOS safari.

This does have some security concerns as it provides information to a potentially bad actor that they did not have before.

The Rolify gem is great if the complexity is needed. Otherwise, I feel like this is a simple enough implementation that would accomplish many use cases as well as not introduce another dependency.

ah.. like it!