However, my question is about "unfulfilled conditions relating to their permanent resident status" FOR MINOR.
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/application-forms-guides/guide-0003-application-canadian-citizenship-minors-under-18-years.html#CIT0003E4
Does it mean he has to be present in Canada 1095 days within last 4 years SINCE he got his PR status or does it mean he merely is not in situation when he may loose his PR status?
Short answer: there's no need to even think about waivers, as it is possible to apply for citizenship for the child you describe in your example. They do not need to have accumulated 1095 physical presence days, and it is extremely unlikely there are "unfulfilled conditions" related to that child's PR status.
Longer answer:
There are three things related to your question:
- "residency obligation", which says you must be in Canada (or live with your Canadian parent or spouse) for 730 days out of every 5 years
(or that you must be able to meet this requirement if it's been less than 5 years since you became PR);
- "residency requirement", which says you must be in Canada (or be employed as a crown servant outside Canada) for 1095 days out of the most recent 5 years;
- "conditional PR status", which imposes specific requirements on some people when they get PR. Examples of this are the, now abolished, requirement to live with a sponsoring spouse for two years, or to establish a business of a certain size within 5 years of landing for entrepreneurs.
The second one is not relevant for minors who apply under 5(2) (i.e. who have a Canadian parent or whose parent is applying at the same time), as there is no residency requirement, i.e. they do not have to have been in Canada for 1095 days in the last 5 years to be allowed to apply.
The minor should not be under investigation in a case that could lose them their PR status, but a minor who applies under 5(2) can have become a PR yesterday and an application can be submitted for citizenship today. Not meeting the residency obligation (the first item on my list) could have caused them to be under investigation, but that's not possible for the minor in the example you give (as they're in Canada right now, with plenty of years left to meet the residency obligation).
The third one is extremely unlikely to be relevant for your application. In any case, conditions are things that would have been noted on the COPR and are usually explained by the CBSA/IRCC officer who does the "landing" interview. The one "common" condition is one for medical monitoring, in which case you'd be aware of that requirement. The only other common one applies to entrepreneurs, and I don't think such a PR status is ever issued to minors.