The Courts and Tribunals Judiciary site has an "e-bundles protocol". Since this is a sign of things to come it would benefit all practitioners to read it.
THE GUIDANCE
4. Where an e-bundle is to be used the following technical requirements should be observed:
(a) PDF format is to be used;
(b) All d...
It doesn’t mention that you have to paginate differently from the witness’s paper bundle. I’m pretty certain that must be a rule.