I could be wrong about this, but, if I recall correctly, it's the other way round. The phone is what has the smarts.

I seem to recall that there is some handshaking going on, where the phone/tablet queries the power supply to see if it can deliver a higher-amperage charge signal. I know we've discussed that elsewhere here on the BBS. Apples, for example, have some smarts where they try to detect if they are hooked up to a cheap Chinese charger, and if so, will only try to draw the minimum from that charger, just to be safe. If they detect that they are connected to an actual Apple charger, it will detect the type of charger (large or small) and then draw the appropriate amperage depending on what it finds out.

What I don't know is how exactly the device goes about querying the power supply. I seem to recall that's the details that we discussed here elsewhere on the BBS a while ago.

So your third party charger thingy will, at a minimum, work correctly for slow-charging your devices no matter what. The only question is whether your devices will be convinced that the charger can deliver the higher charge rate, and then take advantage of that for quicker charging.