this may be true. I was working off the protections for tobacco products. The issue is the iQOS is a two part device. There is the heater, and then there are the “cigarettes” that aren’t, really, which you Insert into it that take the place of vape juice. The cigarettes are technically cogarettes though and as far as I can tell are both where literally everything comes from, and are more or less immune from any sort of legislation. I could be wrong about that though. . Traditional cigarettes are not all that hard to mod. It’s not often done in the USA because BT doesn’t like it, but outside of North America it’s not uncommon.
Various ways I know of off the top of my head right this second without any research:
use something other than an approved insert is the easiest one. They’re basically shredded paper soaked in juice. The paper is made from tobacco leaves which makes them technically cigarettes but just about anything could be used. There’s other stuff too. Dipping is one. That’s a traditional way to treat cigarettes and would work just as well. Another traditional cigarette method is spikes which are pushed into the end of the cigarette. Then there’s machine hand rolls. @stolls seems to know about those. There’s also whatever the cigarette smugglers come up with. Sky’s the limit there.
Everything you just described would be aftermarket "modding" on the device and insert HEET fake tobacco stuff in it. The stuff is sold in a sealed package, and the manufacturer can't make any changes to the approved device/heat sticks/whatever, without FDA approval. They couldn't add 5 drops of water to it without filing an addendum for approval prior to sale.
Well, they could, but if the FDA found out they could issue a warning letter, and if they felt it represented a significant and potentiality dangerous modification or one that altered it's harm reduction "properties", order it off the market. Given the attention that will be focused, I doubt Altria will make a single misstep because there is little doubt how fast the FDA would slam the door shut on anything that might affect a smoking device they approved as a harm reduction product.