Make parent eventseries fields available for rendering in twig

If I understand what you are asking for correctly you may be able to achieve what you need using the Field Inheritance module that Recurring Events has as a dependency.

If you go to: Admin > Structure > Field Inheritance, you can add fields to the event instance (destination entity) that are inherited from the event series (source entity).

For example, if you had an address field on the series you wanted to pull into the instance you could set up a field inheritance like so:

Inheritance Strategy: Inherit
Source Entity Type: Event Series
Source Entity Bundle: default (or whatever bundle you want to inherit from)
Source Field: Address
Destination Entity Type: Event Instance
Destination Entity Bundle: default (or whatever bundle you want to inherit to)

Then on your manage display for Event Instance you should see the address field you can place as you wish. This will then make it available to twig too.