How can I get the full DTV visa sticker in my passport instead of just the entry stamp?

The best of both worlds is in India : you get a evisa, but first time you use it, it’s coaverted to a stamp written evisa, with type, validity date, everything. Didn’t try to enter again but I guess every time you enter they just need this stamp.

When you had submitted a Thai E-Visa application via the Thai E-Visa website thaievisa.go.th to the Thai Embassy/Consulate from where you received your DTV Visa as a Thai E-Visa PDF file via email or downloaded the PDF on the Thai E-Visa website, then you will NOT receive a Thai Visa Sticker in your passport book.

if anyone had physically went to a Thai Embassy/Consulate to submit their Thai Visa application in-person, then they will receive their DTV Visa Sticker in their passport book and will not receive any PDF's.

You cannot get your DTV Visa as Thai Visa Sticker as you already received your Thai E-Visa as a PDF.

Everyone always needs to double-check every Entry Stamp (or sticker or system entry for scenarios where they don't ink stamp passport books anymore) by any immigration officer on every entry to make sure there were given the correct entry and stay period. This self double-check applies to all countries, all the time.

Although it would be nice you only get the small stamp now

You don't. The big sticker is issued by the consulate you attended to apply for a visa in person. If you applied online you get a pdf visa. What you have in your passport is an entry stamp