I believe apples native photo browser can customize file size not sure if pdf is natively supported but surely theres an app store approved app for Mac that is safe or an open source trusted app for Mac or windows
If your sticking around go to an AIS or true corporate store or buy a Sim on lazada.co.th that has unlimited data at a fixed max speed (example 8mbps) either way much cheaper and much more fast data typically.
Moreta I came back to try few weeks ago works great for what it can do. QR works almost everywhere except street food and small family run shops. Will work soon with personal QR too soon
Its what they dtv visa under soft powers was designed to allow though. Now a year in surely people will be questioned on reason for entry on those soft power dtvs