Hi Pippin,
I am an applicant and do not possess much experience or knowledge, sharing what I know so far ;D but would like to share my thought here. again, coming back to a London VO applicant whose travel history was missing, he was contacted by CIO to supply that missing info AFTER he was encashed. looking at that particular case, I understand CIO will contact jolly for that missing doc IF they find his application complete and necessary.
as regards to determination of completeness of the application, courtesy of our friend from Moscow VO MSM-2332 who shared nice piece of info, I share below an extract from the CIO publication (Q&A):
so, if jolly's CC is charged shortly, I understand his application will be found complete, and any missing docs will be requested. I never supplied my children pps, only birth certificates, but personally do not find these docs critical. I read on some Russian forum that certain applicants even got through without children docs...