It looks like there are no guarantees with border bounces either. There are reports on here of people being grilled and asked for stuff that they never had to show when getting their DTV. That being said it appears that the chances of issue free re-entry into Thailand on a DTV are better with border bounce vs. extension. I just want to stress that it's not completely issue free. :)
I always give my DTV printout along with passport and boarding pass. However you would think that as soon as they scan your passport their screen should show your current visa status?
It sounds like the OP used a Thai bank account to show the embassy that they had the 500K when they applied for their initial DTV. That is "probably" why immigration needs to see "their" updated Thai bank book. So this was specific advice given to someone who showed they had the 500K in a Thai bank, not the same scenario for everyone. Probably... 😁