What is a SFRA? Special Flight Rules Area? Especially around Washington DC. I recommend every applicant takes the course that is required to operate within 60nm of Washington DC on FAASafety.gov.
It's also important to know what factors affect stall speed, understand how CG location affects stability and be prepared to convey them in a way that you have a clear understanding and not just memorization.

Electrical System is the most important system on the Diamond especially in IMC.  No backup source of power outside of the Battery. How long do you have before battery runs out?  What equipment is on essential bus? What is your strategy for dealing with an electrical supply interruption. Flight manual supplements need to be studied. Especially limitations on avionics and autopilot. This is very important for instrument pilots. Also pay attention to Obstacle Departure Procedures. If it says STD this means standard departure minimums or one mile visibility. Adhering to these procedures and visibility is critical to your safety on departure.  This includes the minimum climb gradients.

Bank Angle while under the hood should be a maximum of a standard rate. I would recommend a little less. This is an emergency for a non-instrument rated private pilot. 30 deg bank in the Diamond is too much and you risk getting into a descending spiral and losing control.

A "Gouge" is a time honored aviation tradition that allows students who are planning on taking a checkride to benefit from a students experience who previous and recently took a checkride.  Like all of aviation, the secret is in a good debrief.
As members of Oncore Aviation you should benefit from the valuable lessons learned from other members checkrides.
For this reason, I've offered to provide my perspective that come out of our post checkride debriefs that will assist you with better preparing for your upcoming practical test.