Is it normal for Thai immigration to ask for extension application upon visa expiration rather than the typical 30-day period?

The poster recently visited Samut Prakan immigration for a one-year extension on a NON-O visa. Instead of the usual requirement to return in 30 days with an updated bank book, they were instructed to come back on the expiration date of their 90-day visa, which is in about 50 days. They are unsure if this is standard practice or a mistake, considering they thought the rule was to return after 30 days. Comments from other users suggest that the extension process can vary, and typically runs until the visa expiration date, but additional advice on re-entry permits if traveling is also given.