Here we go:Hi - could you please provide the source for asserting that the approval rate for inland H&Cs are "rather low?" Thanks in advance.
1. statistics of the all admissions rates in 2017
https://www.canada.ca/content/dam/ircc/migration/ircc/english/pdf/pub/annual-report-2017.pdf
From which all H&C accepted immigrants were 3913 people (attention those are not approved application as you can have more than 1 person on one application).
That also includes H&C cases where people did not meet their RO requirement, H&C for spouses and children or parents.
Now here is the part of the statistics about appeals.
http://www.irb-cisr.gc.ca/Eng/ImmApp/stats/Pages/index.aspx
What Is a bit problematic, is to distinguish between H&C cases and others.
From this one it is visible, that the highest success rates have sponsorships appeals. (app. 40%)
Removal orders (including refugee removal orders) have app. 20% success rate. bear in mind that they do also include removal order for those that did not meet RO criteria.
This data also contains mix of standard appeal and H&C appeals (which are usually last resort).
So the reality of H&C approvals for refugees lies somewhere between 10 and 20%.
In some cases people will reconsider and withdraw their appeal and in others they will just abandon it. (many of which are appeals without much chance for success).