We find the shooting test element tends to cause the most stress & worry.
Human beings that we are ( mostly ) the level of pressure felt and how it affects the person is a very individual thing. As a mechanical test the 100mm zero target is not that difficult as a function of the rifle/scope/ammo. It is the human element that counts and that is the one that suffers!
As has been pointed out already, the DSC1 shooting test was developed to test stalking accuracy on a practical basis, not a benchrest competition. The person who can hit within 2 inches of their aiming point time after time - under field conditions will ultimately bring home more venison than the guy producing .075" groups from the bench with a crew served shooting machine. No criticism implied or intended in either direction - its about the ultimate purpose.
The stress element is greatly over-looked in many comments about the shooting test. Approaches amongst Assessors/ Trainer vary - but the best have this factor in mind always and do all that they practically can to mitigate it. The format is often dictated by the facilities, but some do it one on one, some in groups. If it's an issue for you, put it on your list of questions to ask when speaking with your test centre. Performing in a large group is not part of the assessment criteria!
Everyone who has been with us in the last few years will have heard my story ( a. its the truth and b. I really do have a very limited range of script material

) - we had a soon to retire police firearms officer. Not your common-or-garden variety, but one who had done SB Anti Terrorist work, Royal Protection etc. His last round successfully down range - and passing the test - he showed clear and I shook his hand. He actually turned grey and just managed to utter ' @uck me, those were the hardest 9 rounds of my entire life... and on the friendliest range!' Once squared away, he asked to be left alone for a bit and went to have a lie down in the heather for 20 minutes.
I have had countless people that I know can turn in sub inch groups, but on THE DAY struggled to keep them in that 4" ring. Some people thrive on the stress, most don't. It's life, not anything to over worry.
If any element of the DSC1 process is concerning you, don't ever hesitate to pick up the phone or e mail etc your training provider - you are not weird nor by a long, long way the only one.
Of course if you really want to pile on the stress you could try using a Blaser
