I recently realize that I always spent a lot of time preparing my work environment before begining my exam. As an example lastly, my settings for .vimrc did not work like on RHLS training lab servers. So it was a real pain working on yaml files. Can we dicuss about some tips that can help you gain time as we know that Red Hat exams are all about performance where time and speed are fondamental.
AFAIK the exam environment brings all software at their installation defaults, except when explictly noticed on the exam tasks. So you cannot expect to see any pre-customizations to things such as .vimrc, but you can make any customizations you want.
It is your choice to spend time configuring your text editor or performing exam tasks. I used to spend some time during my exams installing a few X packages on exam VMs just to be able to run gedit over ssh -X. :-)
You have access to everything that is on RHEL repos and any layered product repo that is part of the exam. You cannot download stuff from the internet, such as a text editor that is not on RHEL.
Beware that such customizations, as they take up disk space and RAM on the exam VMs, may impact your ability to perform some tasks, if the exam VMs are tight on resources. Again it is your choice to perform customizations, if they end up hurting you, you cannot complain.