Think you’ve hinted at it in the end of your post - best to do BT efforts in slope mode so you can actually breakthrough ‘fully’. If it’s been a long time since a BT that’s especially important (slightly annoying if auto mode finishes an interval when you have something left in the tank). It may be worth increasing the intensity a few percent (or more) as well, given its been a while.
In the end, what’s important is that you go to failure after drawing down MPA. When you think you’ve got nothing left, try and sprint. Then recover for 10s or so then go all out again (and again if you can) 