I recently applied PRTD for both of my parents as their passports and PR cards were stolen from Mumbai. I am a Canadian citizen living and working here, however my parents are based in Mumbai. I applied for PRTD on basis on H&C grounds due to my mum's illness and the specialized doctor based in India. I applied for Multiple entry PRTD's, however only my dad who is a caregiver got multiple entry PRTD valid for 1 year, my mum got a 6 months single entry PRTD.
For purposes of assessing your parent's status and whether they should be allowed H&C relief for failing to comply with the RO, your status, location, and employment are largely irrelevant. Your residency in Canada may carry some but not much positive weight in the H&C analysis because your residency here is a ties-in-Canada factor for them. But your status as a Canadian citizen carries no weight (or at the most very little).
In terms of questioning the difference in the PR TDs issued, remember that H&C relief for failing to comply with the PR Residency Obligation is an
extraordinary remedy. There is no entitlement to a particular outcome.
It is important to recognize that as an
extraordinary remedy, it is for a past breach of a PR's obligations, for their failure to comply with the RO up to the date the relief is granted. It provides NO relief for a failure to comply with the RO in the future.
So, make no mistake, if your parents do not come to Canada to stay long enough to get into RO compliance before they leave Canada again, if they leave they will again be at risk of inadmissibility proceedings that could result in the loss of their PR status. This includes the parent with a multi-entry PR TD, even though their risk would less than a PR who needs to obtain another PR TD to return to Canada.
The grant of H&C relief is, essentially, giving them an opportunity to return to Canada to stay. Make no mistake: that is to stay at least long enough to get into compliance with the RO.
That said, if the PR has a multi-entry PR TD, or obtains a valid PR card,
brief periods of travel outside Canada should have minimal risk. But to be clear,
H&C relief for a RO breach does not restart the RO clock.
Overall: for either of them, even if in the meantime they apply for and obtain new PR cards, if they leave Canada for a significant period of time, that will be risking their PR status. The longer they are outside Canada, the greater the risk.
Potential Escape Valve: if one could stay in Canada long enough to get into RO compliance, and stay enough to remain in RO compliance, they could sponsor the other for PR again if the other loses their PR status.