It's not easily swap-able for chip upgrades. This assumes an upgraded chip is pin- and signal-compatible, which is almost universally incorrect.
if you've got the skill to modify the USB stick for external power without wrecking anything, it can be done with the stick as-is. This idea has been presented I don't know how many times in the seven years I've been building high-performance stick miners and it gets dismissed every time. It will continue to be dismissed every time. If you want external power, you no longer want a stick miner.
To be honest, it would be cool to e.g. have a second USB connector so you can use 2x 3A ports with one chip, to really get the last bit of performance out of these insane single chips.
However, I see the cooling as an issue. Already 15W on such a small cooler seems to be stretching it, so I'm not sure it would be safe to push this stick-sized design further with even more watts.
Also, pod miners?! I heard his words! The lord is back!