CW starts the under consideration period from the day you apply. If you apply 45 days early you would have have your new extension done,
FYI you can get a re-entry permit for the under consideration period.
If he enters and immigration insists that the visa be used he could get a single re-entry permit before leaving Thailand to keep the remainder of the 60 days valid when he enters Thailand again.
The government hospital on Sappasit Road has a good reputation.
122 Rd Sappasit, ตำบล ในเมือง Mueang Ubon Ratchathani District, Ubon Ratchathani 34000
Full name for it is "Sunpasitthiprasong Hospital".