Can my friend extend her stay in Thailand after her tourist visa expires by border bouncing?

A user is inquiring about the possibility for a friend from the UK to extend her stay in Thailand where her tourist visa is about to expire soon. She has already extended her visa once and is looking for options like border bouncing to obtain another 30-day stamp without renewing her visa. Comments indicate that leaving Thailand and re-entering may be a feasible option, but using an agency could help ensure the process goes smoothly.