<p>I know you should, like an infant, never leave your printer without surveillance.</p>

<p>But sometimes we all do, trusting our double thermistors and heat runaway configurations. But electronics fry and who says there is no danger even after the print job has finished and it's cooling down, still hooked up?</p>

<p>I have searched but smoke/fire detectors come in a wide range of varieties: </p>

<p>They can be battery powered or hardwired, they detect different things: carbon monoxide, heat, smoke..., they thus also have different detectors like photoelectric sensors, ionization sensors or both. We also print with different materials...</p>

<p>So what's the best safeguard for my 2 year old (CoreXY ^^)?</p>

There’s no huge difference between both. The printing settings like temperature and printing speed are practically the same. But the PLA+ have a much better surface quality and it’s slightly more bright than normal PLA. Another difference is that the PLA+ it's more effective in bridges than PLA.
If you want to the comparison between PLA and PLA+ go right here,
PLA vs PLA+ (short review)
. This post is an awesome experiment with both materials.