SL has a minimum size objects can be scaled to. you need to cheat up the geometry for anything under .01m

the way i do it: make a box. size that box to the size you want your bounding box to be, and in the place. this also helps LOD issues (larger bounding box means it drops LOD slower BUT also you get the higher LI potential, so don't make the box too enormous without a good reason), and can be used to change pivot points, say for a door (the center of that

box is the point it pivots around). triangulate that box, take one vertex of one triangle and put it in one corner (or keep it there), take another vertex of that triangle and put it in the opposite corner. delete the rest of the box, keep that one triangle. snap the remaining corner of that triangle to where one of the other two corners is, so you have a

diagonal line. merge this diagonal line with your actual object you want, if you haven't yet (i often make the box while in edit for it OR i do a shortcut of just dragging a triangle without adding the box, but starting with the box makes it easier to understand). now when you go out into Object mode in blender, it'll say that object is larger in the size

DO NOT merge duplicates for this triangle, ever. this triangle must remain a triangle- it MUST have all 3 points or it gets discarded. the making it look like a line thing means that you don't need to worry about the texture for it, it won't render. some creators make entire invisible full boxes around things.

last picture is with bounding box visibility turned on so you can see the weird angle i took the pictures from- that box there isn't actually there at all.

(but if you started off from a box as above, that would be the box you started with, and then the line from corner to corner is the bit you want to end with)

Allegory: I love you! You're always so incredibly helpful and the information you give is easy to understand! Thank youuuuu!!!!

DecemberLarkham: back in ye olden days before mesh, we did crazy ridiculous things with cutting and hollowing and turning prims inside out to get them small! and sculpts involved leveling the sculpt texture to cut the colour range (as colour range was how they defined coordinates)- this is just the newest iteration of the hack, hahah

Allegory: Haha, yeah I remember that. Good ol days of trickery!