Your post sounds so encouraging!....
It seems you have many boundaries covered...
I know exactly what you mean re: gratitude over a second chance
my RAS also got another chance (and it wasn't just his second!)
he got into a program (long term also) that has saved his life so far...
not every addict gets the opportunity to try again in a safe, nuturing environment (again, no country club lifestyle...good clean hard work and a safe bed at night)
I am praying that your son (and mine) take this opportunity and use it to turn their lives around