have no idea my man. I've not gone through that border since 2015 but reading everything in this group it's almost like going into Tijuana from the USA. Push a button and if it's green they let you in and if it's red they don't. I thought they only denied serial border bouncers but this Ellie says other types of travellers are getting denied to
If you want 150 days you can do what I just recently did. 60 day visa, 30 day extension, 2 land border runs. You can get another extension after your first visa run if your landlords cool enough to do another TM30 after your border run but my landlord is a slack ass so I did 2 border runs. Either way will be fine for 150 days