I would like to get a direct answer from the Webmixer team/dev here
Incoming address is valid for 7 days (168 hours). All payments made after this time will be ignored.
If we have the case that the user sends a certain amount of BTC to the generated deposit address, the mixing process is completed on the same day. Is the same BTC deposit address still active?
What will happen if he makes a new transaction and sends BTC the next day (so still within this 7-day period, while the address is valid)?