Would it be possible in the future to completely remove the need for USB in Fusée Gelée?
ktemkin has stated before that f-g is a tethered exploit.
Others might be working on kernel exploits to remove the need for a powered USB device (jig still should be needed) - but at the potential expense of loosing online capability (modified system "portion" that N potentially could detect). There are no ETAs on that, just attempts.
Also modchips (as in not dongle thingies) should be able to do just that in the future (as they could do the same thing as the usb device and the jig does - from inside the console) - with an entirely unmodified "system" section - so potentially without loosing online (for games you bought).
As far as the failoverflow "coldboot video" is concerned - I dont know if they have stated if it was "software only". In any case the current state of information is, if you want "software only coldboot into CFW" - 1.0.0 still is the most likely candidate. And all others most likely not.
Firmwares up to 4.1.0 should be getting "software only" hacks in the "nearer" future - but at the expense of potentially "loosing online" (original firmware on the console has to stay "low", and the CFW loaded up can probably be detectet and consoles banned) - also - those hacks (for up to 4.1.0) are very likely reliant on browserhacks - so would require you to be able to go online with the Switch - and might take longer to "boot into CFW" than jig solutions. (The last part we don't know - its speculative.)
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The "i dont want to care - I just want to have" solution will be "jig and dongle thingy" for quite a while. Especially as it potentially wont have Nintendo banning you easily - as one of the benefits.
People on lower firmwares, might have the benefits of getting pure software hacks in the future - at the expense of loosing online (and they might not be the fastest to set up after cold boot (if they are not on 1.0.0)).
People with modchips (as in not the jig and dongle thingies) might get the best of both worlds also in "i dont wan't to care mode".
If the manufacturers are intelligent enough to only have it short pin 10 when its needed as supposed to always. (Always = higher ban risk.)
Notice - how the "i don't want to care" methods are related to things that people make money with. Strange how that works..
(The jig and dongle thingy by proxy - because whoever makes the most portable/usable dongle thingy has a heads (/leg) up. And chinese manufacturers might win that exchange over people trying to use "homemade solutions".)