How to get auto-completion in RStudio?

Use the autocomplete option:

eplusr_option(autocomplete = TRUE)

Underneath, [makeActiveBinding()] is used to add or move active bindings in [Idf] and [IdfObject]s to directly return objects in class or field values. This will make it possible to dynamically show current class and field names in both RStudio and in the terminal. However, this process does have a penalty on the performance. It can make adding or modifying large mounts of [Idf] and [IdfObject]s slower.

How to control the maximum number of parallel simulations?

Use the num_parallel option:

eplusr_option(num_parallel = 2)