I don't know if the risk is greater. Not sure that they are watching u closely after a ban. I got a perma ban, overturned into 72h and I told to myself, screw it and tested the toon after I was unbanned. Was gathering/instance farming for like 30 hours straight and nothing happened at all and the toon is still going strong. But mby I was just lucky, who knows.
I still use my bot accounts after a ban. Safest bet is to just sell the account on Craigslist or another site and buy a new one.
the same risk before you got banned, although nobody knows but 72h bans are usually derived from player reports.
The OP mentioned for 72h reduced from perma-ban, but still the chances in my experience are huge in the next several days after the ban, prolly 3 days or a week, nobody knows for sure, but after that its perfectly safe! (Read: safe as before the ban )