Do I need to carry a bank statement for immigration clearance at Suvarnabhumi Airport on my third entry on a DTV?

There will be no difference

Print out the PDF of your DTV visa and hand it to the officer along with your passport, check that you get the correct stamp when they return your passport.

No need to carry a bank statement, in case the want proof of funds they will ask you to show your internet banking on your phone

No

Never have, entered many times

I recently re-entered for 3rd time. No questions were asked. In case IO asked you the financial proof, I think mobile banking statements on your phone should be fine although majority of DTV holders are not asked to show bank statements. But, entry permit is at the discretion of officers so it’s good to be prepared for possible questions!

No, you are not normally required to present a bank statement every time you enter Thailand on a valid DTV. Most travelers report smooth re-entry at Suvarnabhumi without being asked for financial documents, especially with a clean travel history. However, Thai immigration officers still have the authority to request proof of funds or supporting documents at their discretion, so it’s recommended to have at least some accessible financial proof if possible

It’s almost as if smartphones and online banking wasn’t invented yet.

You don't need to carry a bank statement. It's extremely unlikely you will be asked anything.

No you do not