for speed detection a single sequence of i2c commands is enough ( first i2c command from booston )
the kernel don't need a circular timer for stable vbus for speedcheck
a single 32s pulse** for first hardware testing, and a second pulse for full - high selection ( ** turned off when not necesary )
then set a modified procfs. echo A(utosense) > /sys/.....?
a simple program from userspace can check this output then start with the corect speed.
i think is there is a great complication stopping bme and start a circular timer from kernel space. for sure the timer can do the job easy "from inside"

i will make a modification in the script with single i2c command for first speed ckeck.
this avoid ugly killall booston in first step
a simple daemon can watch ID* pin so triggering the host will make things simplier and natural

*with filled CA-157 cable or uAsoket

please provide feedback about the script (PM or .. your choice )