There is no waiting period. You only become tax resident after 180 days in a cal year but that does not delay changing banking etc information to start your clock.
The part of this which can cause issues is that modern KYC (know your customer for financial services) asks for utility bills or bank statements (or government correspondance), and many western banks do not like overseas residents and some even close accounts if you change to a Thai address. Secondly Thai utilities dont come in english text or with tennants names on them (internet bills do).
One step around this is to go and get a letter of residence proof from immigration as soon as you do your TM30, and then go to a certified translator to have that officially translated. If you can change bank statement do so also and finally if you rent a house and get broadband that can be easily in a western name. Those things working together usually passes KYC.
the LTR requires multi 100k USD investment in Thailand or large proven incomes. Both of which have a clear direct benefit to thailamd in attracting hnw individuals and big spenders.
The DTV visa posters seem to be stressed at the idea they might have to show 500k thb.