I always get a re-entry the same time as I get my 1 year extension even if I have no intention of leaving at the time. For a 1000baht it saves a lot of hassle even if don’t use it.
Remember to get a re-entry permit before you leave on April 12th otherwise you will lose your one year extension and will only be given a visa exempt 30 day stamp when you arrive back in Thailand.
Just to let you know for 90 day reporting in Jomtien you do not physically have to go into the immigration building. You just go to the desk outside on your right as you enter through the gate. Drop your passport and forms etc off and go back an hour or 2 later. No waiting around.