The latest revision of the Paycheck Protection Program appeared to be a victory for the most vulnerable small businesses, offering more generous relief to companies like solo ventures that were eligible for only tiny loans — or none at all. If only they could take advantage of the changes. President Biden announced an abrupt overhaul two weeks ago to funnel more money to very small companies, some of which qualified for loans as small as $1 under the old guidelines. But the Small Business Administration updated its systems only on Friday, and with just three weeks before the program is set to expire, some lenders say there just isn't enough time to adapt to the changes.