If you believe Canon 4 supports Baptism of Desire then you must also believe in Holy Orders of Desire, Matrimony of Desire, Communion of Desire, etc.
I heard a Priest once during a sermon mention ‘confession of desire’.
IMHO that is the last thing the laity need to hear considering those on their deathbeds who need family members to go to great lengths to get them a Priest for Last Sacraments!
If someone stops to think ‘oh well at least grandma/grandpa can have confession of desire, they’ll go to Heaven.’ NOT GOOD. It’s a slippery slope one way or another with this ‘Sacraments of desire stuff’.
Before I had even heard of BOD I did have a general idea for how Baptism worked and always believed that God would provide the Sacrament for those destined to be with Him in Heaven. I think also hearing stories of people in car accidents having a random person show up on the scene to Baptize them could have helped with my understanding also.