Clarification.
Yes, you need to have a hot-sim-enabled commlink in order to experience the hot-sim-level programming of a BTL chip. You can indeed run the chip on cold sim, and experience the sensations and emotions on the safe, 'bland' levels; those controls are on the commlink. While it is possible to have optional programming on the chip enabling hot/cold sim selection, since it's always going to be on the commlink, that optional programming isn't generally going to be found on the chip itself; programmers are simply going to turn it up to 11 and leave it there. In regards to the commlink, since hot sim is technically illegal, you can't buy it ... but it's generally been considered a relatively cheap and easy mod, and one that's always set up with an on/off switch.
Now, since BTLs are hot-sim, and BTL dealers want you to buy again, most BTL chips have a 'counter' that gradually turns down the level of sensation, enticing you to buy a new chip to get that great better-than-life 'high'. Running the chip on cold sim is still going to run the counter down, so you're blowing money (as it were) on sim sensations you aren't getting. But you can indeed run the chip on cold sim. As a note, you will experience the emotions and sensations encoded on the chip - it's a simsense chip, after all - but you won't experience it at the ultra-high, addictive BTL-experience levels that the chip is instructing your (hot-sim) machine to channel into your brain.
