You may find these discussions of interest,
Remustering while at BMQ
https://army.ca/forums/threads/37141.0
Remustering after BMQ?
https://army.ca/forums/threads/82143.0
remuster during BMQ
https://army.ca/forums/threads/72382.0
remustering during BMQ?
https://army.ca/forums/threads/113425.0
Occupation Transfer at BMQ
https://army.ca/forums/threads/118448.0
Change of Trades during BMQ
http://army.ca/forums/threads/23075.0
OT during BMQ
http://army.ca/forums/threads/93566.0
Occupational Transfer in BMQ
http://army.ca/forums/threads/94670.0
etc...
Edit to add
Can only OT after DP1? plus speaking with a BPSO
http://23.21.69.35/forums/threads/116849.0
How to OT after Basic Training?
http://army.ca/forums/threads/114651.0/nowap.html
HELP with a VOT-U
https://army.ca/forums/threads/112593.0
"I have BMQ only"
VOT between Elements after BMQ
https://army.ca/forums/threads/121030.0
etc...