Adventures across the 3rd dimension

I was thinking I'd dedicate today to getting all the collision boxes and "interaction positions" correct for each new item, today. But now I'm not so sure. 

I decided to be thorough about it and make little sketches with each items size and placement in Blender, but with the axis of Unity and go from there. Checked the first item and it aligns perfectly (and I found a mistake I made which explains why the little fellas was entering the privy through the wall instead of the door ) but that's pretty much where it ends. 

If it wasn't for the sink I'd think it was just another change of axis... I mean, you have X Z Y in Blender for left-right, up-down and closer-further away... And then in Unity that turns to XYZ and what was negative X or Y in Blender becomes positive X or Z in Unity. So maybe they went back to negative in game? But that doesn't explain the sink. Where it seems like the collision box somehow was rotated 90 degrees AND displaced along the X-axis even though I did no such thing!  

(And that's just the collision boxes. Interaction positions - where the foundies stand when building the item - seem to also be entirely backwards. So what's positive Z in Unity should be negative Z in the code. I think. )

Edit: and in spite of "fixing" the privy, they still enter it through the wall. Just the other wall.  

Edit2: And after some thinking I realize that in my "thorough" little sketches I completely forgot to take into account that switch of positive and negative between Unity and Blender, so I think that would explain most of it. Except the sink and how one of three toilets all made to face the same direction loads facing the opposite direction, in game.  

Edit3: and now one of the collision boxes which previously worked fine (but I decided to move the item a bit in Blender so it needed to be adjusted.... I think...) seems to have rotated 90 degrees and doubled in length. Without my changing it's size...   

Edit4: Still just trying to get things right for ONE out of nine items. Trying to get my head around what I should go by, but not having any luck. Should the collision box be located according to the coordinate system or the center of the item???  This is the result I am having, so far.... Seems coordinates are scaled somehow for some utterly inexplicable reason. (The reason the collision box and the item doesn't line up currently is because I chose to set it at zero to see what happens. Not that I even know where it ends up when I set it elsewhere since it's invisible and the collision effect itself seem to change randomly anyhow...)

 

Edit5: I posted a "help me" on the founder's fortune forum, not that anyone reads it anymore. Everone who posts there just care about the new game InfraSpace. To which they just added modding support too, but I'm not sure the issues will be similar... Anyway, I'm starting to suspect that it's because I haven't "applied transforms" to the items in Blender. Next problem is.... I don't know how to do that. As usual the guides just refer to a stupid shortcut that seems to do nothing, probably because I am in the wrong editor or something. Or maybe it doesn't work when you have a whole collection of items instead of one joint mesh? *whines* I hate feeling stupid.  

I found it in the menu, yes. But I still don't want to make everything one mesh which means having to do it to each separate piece. I think. And I have a couple of pieces it refuses to do, for some reason...

I haven't checked if it works yet, either, as changes to the items mean I have to make a new asset bundle... and it's bedtime. Working again tomorrow.

I can select all but if I do it won't apply anything.
"Cannot apply to multi user"

I don't know if only applying scale & rotation makes a difference? The guide I read said to use that particular choice...

I bet MY Blender won't want to make several objects single users anyway.
I do know I can do that when I want to "disconnect copies" from the original...