My brain is in "slow-mode" currently, so I'll need to be sure I get this straight :
Your printer is putting down 3 layers of support first, and you actually want a "immideatly to bed" with a skirt around ? Yes ? (.... which is how I use Simplify3D to allow nice fitting of multiple part printjobs).
Here's what my slow brain fails to grasp or I simply misunderstand what you're syaing :
1) "there's always 3 layers of support printed before the actually part starts printing". (okay, I get that)
2) "the first part layers droops due to nothing beneath it". Eh ? What about those 3 layers then ?
Or do I have to understand "your printer prints "starting 3 layers above the printbed surface" instead of ON the printbed ?
If so, my first idea would be check bed levelling, which on my prusa is a pure mechanical callibration of the Z-axis.
Second would be looking at experimenting with the Z-offset.
https://forum.simplify3d.com/viewtopic.php?f=8&t=2210
I expect you're using the Idea builder profile that comes with S3D ?
I'm probably misunderstanding something here. If so, just asume I'm currently too daft to understand your explenation. but I'll try to help you as good as I can.
But simply said, if you throw a G28 code at your printer, is the nozzle "floating above the bed" then too ? After such a command, your hotend should be able to "hold down a single piece of paper" between itself and the printbed. (printer control ---> G28 in command line ---> send). If you can slide a piece of paper between nozzle and printbed without any trouble at all, there's something wrong with the Z-Axis for sure.
In worst case, you could export the G-Code and send it to me, I'll run the G-Code on one of my printers using S3D to see what happens. I'll use the P3Steel Prusa for that as it's a cartesian printer like your Dremel is.
Or you could do that too : take that model, export the G-Code and see what happens if you print it with your specific printer's Dremel slicer or download Cura to see if the problem is inside the G-Code or not.
Not sure if you've ever played with Cura, but it is a breeze to use and to set up. Quality is a bit "meh" sometimes compared to S3D -especially on small details with nozzles of .30 and smaller-, but it's a solid piece of software in terms of stability and the quality is pretty good when using "standard" ,40 nozzles.
Don't worry, we'll get there. But I admit, I've not yet come accross that problem either. ****load of others yes (which I all got solved in the end), but not that one.
My only openstanding issue with S3D remains that raft-sepperation is broken since version 3.x. This went like a breeze in 2.X, starting 3.X the only way to have some kind of easy raft sepperation is to print the raft at 100% (contradition maybe), but compared to raft sepperation in say Cura or even the older 2.X versions raft sepperation is downright terrible. (Yeah, although I try to avoid it as much as possible, I used rafts sometimes. The Prusa can print up to 330mm in heigth here, and I've had models toppling over if their footprint is very small and it can't be solved by rotating the part and reslicing it into multiple parts is an even worse option ...)
In the mean time you'd do good to contact S3D's support just in case. Who knows, maybe they borked up something in the predefined Dremel profile ?
I'm convinced you'v already checked this, but just to be sure
https://www.simplify3d.com/support/tutorials/rafts-skirts-and-brims/
Also just to be sure, your part IS 100% flat on bed and not slightly rotated over the X-axis ? (Again, probably not just asking)
Myself, I'm currently optimizing my main printer to use PETG using S3D.
The first prints I did with that stuff and S3D came out so bloody nice and smooth I'm pretty sure I'll abandon PLA printing for most stuff, and the added strength of the PETG will allow me to use it instead of ABS in 95% of the cases.