Don't have enough time at hand to go through all this thorougly right now. But...
these are all designed around 0.2 mm layer height so no guarantees will happen at any other layer height
I've never modified parts afterwards to make them vase mode compatible, when I did this it was from the
start when designing something. But I've never ever managed to produce a file which would only work at
a certain layer height... and I'm having a very hard time trying to understand how such a file would be
of any use across different slicers unless somebody knows the internals of them VERY well.
Take layer height for example. If I set layer height to 0.2 but first layer height to 0.3. What exactly will the
slicer do, will it slice a 0.3mm high slice of the model or slice 0.2mm all the way through and simply "scale"
the first layer according to the desired height by adjusting height/extrusion amount? Are all the other layers
now "offset" by +0.1mm because of this? (I guess it will slice 0.3mm and 0.2mm for subsequent, but can you
answer those questions for sure?)
And yes, what you mentioned about the starting points might be the cause. In vase mode you will always
get 0.20mm per completed loop, increasing at edges/vertices of the model file. A very easy example would
be a simple 20x20x20 cube in vase mode. Depending on the start point you will have one of the four corners
always at 0.2, 0.4, 0.6 and so on while the others end up at .25, .3, .35 and so on. And I'm wondering if it's
possible at all to precisely tell what it will print like before seeing the actual gcode preview. Or maybe it's
completely irrelevant while slicing, we simply can't say for sure.
The problems you're facing here aren't really exclusive to 3d printing. In the past I've been doing some
fluid simulations. It's great to have a simulation crash after 90+ hours because one or two particles of
the simulation found their way through a glitch in the mesh... and while many programs got better at this
there's still no universal solution to those problems which will work in all cases. PS does create some stupid
artefacts at times, especially when using Arachne right now - so it's not flawless in all cases. And let's not
forget it wouldn't really print those models in vase mode at all unless the default value for slicing gap
radius is set to 0. So much for "the slicer should ignore tiny things", sometimes it should NOT!
And if S3D started forcing vase mode if selected I'm pretty sure the first thread complaining about
"two objects on plater but only one in preview" isn't far away...
Many of the things here remind me of another problem just recently on this forum. It's another one of
those problems which is hard to fix or properly detect at all times. Imagine I handed you some flat mirror
tiles, 12 pieces in total. Now I tell you to put the reflective sides on the outside of two boxes you have to
make out of those tiles.
Pretty easy at first. Now move the boxes together so they're touching on one side. Even if glued together
you could cut them apart and cleary see which side belongs to which box and what direction it was in.
Now imagine the mirror tiles having a 0 thickness.... like the planes inside a model file. You have two mirrors
in exactly the same place and have to say for sure which one does belong to which box.
Ah, just remembered I added a video, here it is:
https://www.youtube.com/watch?v=uBYvI0YeYyc
So while in theory the simply duplicated box STL is absolutely clean and flawless it still manages to
irritate the slicer when touching each other.
I've just seen so many things going wrong in different programs when handling geometry from other
sources, but I have to come across a model yet which I exported from CAD and does not slice as expected...
And while vase mode in PS seems to be more robust it is often completely useless, because you can't really
combine vase mode sections of a print with layer by layer printing in the ways you can do in S3D. :-/
If some of the problems get caused by the holes starting/ending on different z heights although they're meant
to be at the same height maybe slightly increasing the cut width might help to level out the differences.
But hoping for a software solution that will always exactly know what the user is expecting... nah, that simply
won't happen. Some might have better repair functions but I don't like to rely on those.
To me personally it's pretty easy. If a model fails to slice in 3 out of 4 slicers I have a very close look at
that model file.
Just had a look at the stackable drawer thing, won't even start to list the errors in that file.
(Edit: I don't know why but I can't attach the image. It does show up in the attachments and is uploaded
but the "Place inline" button simply doesn't appear... o,O)
And another edit. When trying to post this I got a timeout message. So this is the last state I happened
to have in my clipboard, won't rewrite everything again.
This geometry stuff can be way more complex than most people think. And each time a model is handled
in a different program this might do things differently. Some tools only work on quad surfaces, others
require triangle meshes. Unless you can say exactly how a model was treated along the way you're simply
destined to run into situations where no auto-repair feature will help you.
Mesh errors are very common, if you can come up with a solution to this there's quite a lot of people
interested in that one... ^^