I guess it pretty much depends on how your active brigade handles the NS unit.
Too bad my brigade that is incharge of the NS units during my active days are super on, the reservist MOs are all given instructions on how to handle the MC issues.
But on another note: If you do have urgent and valid reasons prior to incamp, just talk to your NS CO/OC/PC, even if cannot defer, arrangements can be made. Like last time, the NS CO gave all part-time students stay out for studies and book in by 630am next morning.
The NS CO/OC/PC are also working ppl, compare to the regulars, they are more understanding towards reservist, need not necessary have to keng on every ICT one.