I take it you don't use the auto gates, then do you need to do a TM 30 in 24 hours still or can you leave it for a while? What do you do first transferring the extension to the new passport or the TM 30 first?

Which immigration office? 

Here is form some immigration offices use (eg CW) 

It lists required docs at bottom of form.

https://aseannow.com/applications/core/interface/file/attachment.php?id=995063&key=4ad28e64c063398b61d0a726240743c6

 

Be aware that some offices eg CW are requiring bank book and photocopies to check financial compliance.

You can do transfer of stamps at any time. 

Could leave it till when you attend immigration eg for TM47 etc

11 hours ago, proton said:

I take it you don't use the auto gates, then do you need to do a TM 30 in 24 hours still or can you leave it for a while? What do you do first transferring the extension to the new passport or the TM 30 first?

There are no entry auto-gates.  Those are only for exiting Thailand.

19 hours ago, DrJack54 said:Be aware that some offices eg CW are requiring bank book and photocopies to check financial compliance.

You can do transfer of stamps at any time. 

Could leave it till when you attend immigration eg for TM47 etc