This is upon to embassy discretion. You need to ask them what documents are sufficient for them. Some embassies are ok with email appointment in hospital others require full treatment plan stamped with wet ink.
Please re-read and explain DTV. Put aside all? How does officer know what DTV visa sub-type you have? If it's a random check -> no difference to ED. You simply cannot expect people to have all documents at entry point neither you can expect institutions to answer immigration calls
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. If it's a requirement -> thailand government will change the rules but at the moment nothing is official.
So you want to create immigration queue? Please EXPLAIN how the immigration officer in the booth know what DTV visa you have. Either he has to inspect all or none. ED -> people study thai and cannot answer basic thai. DTV what do you want to ask them? To show 500k in bank account? You are naive. You want all of them to put aside and question them on their documents? They can check outgoing flight genuinity on the spot but you really think they can call gym and ask if it's genuine document. What if the gym doesn't answer the call? You are not allowed entry? Please EXPLAIN
Unrealistic, the officers at immigration booths are not trained and they cannot be selective or verify what you tell them. The immigration IT will not tell them what kind of subcategory you have. And you cannot just employ immigration officers to do police.
While you have good intention that DTV visa allows remote work, it would harm the others who just want to answer questions of immigration officer (border bounced, visa exemption etc.). Publicly admitting it is even worse (it's not anonymous post)