For most models in xLights, there are three places where you can drop effects. The main place would be on the model itself (the first line in the import dialog that you see). In general, when working with xLights, 90% of the time, that's where you are dropping effects. For most imports, that's likely where you want to import the effects. Not all three, just that one.
The second place is "per strand". This is relatively rare. However, if you have a Mega Tree or similar, you can put a "On" effect on just a single strand and that entire strand will light up. The place I've seen this used often is multi-level pixel stars. On a Pixel star, each layer of the star is a separate strand. Thus, if you have a "chase" you would like to along the outside layer, you can drop a chase on the outside strand. If you just want the inside layer to light Red, drop an On effect on the inside strand. Also, for multiple arches, each arch is a separate "strand". If you just want the second arch red, drop a red there. First one blue, drop a blue there. This is the second line in that import dialog.
The third place is on the individual nodes. That's the third line. The common use of importing at that level is for things like Monster faces where each node is a separate mouth or eye or something. Example: LOR channel named "Monster 1 mouth O" gets mapped to the 5th node of the monster xLights model. The "eh" channel mapped to the 4th, etc...
For AC model like you have where it's a 1:1:1 correlation, it's relatively irrelevant which of the three places you import it. I would suggest the top one. For more complex models that aren't a 1:1:1, it's something to pay attention to.
