In addition,They have the same processing for its ShenGen part of it I believed. You can apply after your TEST but this is also a puzzle thought for some on this forum (applicants) were invited for oath after a few weeks, others are invited on other forum in at instant (after their test), others are invited after a month or after 6 weeks. But in my friends cases, 45 days to now they are still waiting for the Oath in Regina. If you will ask me, better discuss this to the CO and ask for your Oath date. Honestly, it is really unpredictable because majority of the applicants here as posted were given 2 to 4 months to wait for an oath including my friends.
If in case the Officer told you that the Oath waiting time is 2-4 months (for example) then you still have time to apply but I honestly can not predict any for this matter.
All the best on your Test. Good luck.