I created a SVG that comprises  2 layers. One is made up of a rectangle that has an offset to create what looks like a stroke. It has to be a rectangle as the line needs to be a shape 0.5mm wide to cut in my Beam Studio program. On this first layer there is also an inverted clip to create a gap in each side of the rectangle. The second layer is just a cut layer. 

When I import into Beam Studio it shows correctly, however says it will take 3 hrs 40 mins to cut. It should take 10-20 mins max. There is no background layer, so that is not causing the issue. I even tried converting to a plain SVG with same issue. A PNG reduces it to a bit over an hour, however I feel there is something in the file that is causing this issue. File is attached. Appreciate any advice.

I'm not seeing any clipped objects. There are two unused path effects hidden in the defs that can be removed by File>Clean Document.

Are we looking at the correct file?

Thanks, yes it is the correct file. Firstly I tried cleaning the unused path effects (earlier attempts at trying to do an offset). Imported into Beam and nothing has changed.

What I did is on the 'Layer 1', I used earlier advice from the forum (thank you!) to create a rectangle 3mm high the full width of the rectangle, centred it, changed it to no fill and then did a Path/Clip/Set Inverse Clip to create a gap halfway up each side of the rectangle on Layer 1. As shown below.

Sorry Tyler I just realized I have given you some incorrect information. I tried to create the gap in the sides of the rectangle using an inverse clip, however it resulted in a faint white line around the rectangle that was clipped to create the space. I ended up having to create the 3mm rectangle that would serve as the item to be clipped, and then do a Path Difference to create the gaps in the side of the rectangle.

I´d try the following: 

Thanks @Polygon, unfortunately did not work. It still says it is going to take 3 hrs 40 mins. I am not sure what I am doing wrong. These are the steps I am following:

1. Create a rectangle 95mm x 58mm, (with rounded corners using edit path by nodes)

2. Duplicate rectangle. Redimension to 94.5mm x 57.5mm, align horizontally and vertically

3. Path difference, to create an 0.5mm border shape only (essentially creating a rectangle shape that is 0.5mm filled along the perimeter, with the internal section removed). The reason being is I need it to be a shape and not a stroke to ensure Beam Studio will cut it to 0.5mm thick

4. Create a 3mm gap on each side of the rectangle using the method you showed above.

When I import this into Beam Studio it is saying it 3 hrs 40 mins. I know it is cutting a shape, albeit only 0.5mm wide, however this is excessive. Anytime this has ever happened upon import, there has always been something wrong with the file.

One thing I have noticed is when I select the object there are two smaller rectangles inside of the main rectangle. I don't know what they are, or how they got there. They are not on a separate layer. I have changed the fill and deleted them and exported the file and still am having the same issue. This is with a clean install, and they appear each time I create a new document.

 I´d try File->Clean up Document and check if these "ghost" objects will go.

Why do you need a double line for cutting?

And what is the estimated time frame when you just send one simple rectangle?

Thanks, I need to create the inner line as a shape (rectangle) so that Beam Studio will cut to a certain thickness. Otherwise it will just recognize it as a thin line. I am creating a stencil that allows a scalpel to follow a shape, hence the need for a thicker line to be cut. The outer rectangle is the cut line to create the actual template/stencil itself. The gaps in the inner rectangle are to hold this section in place, otherwise the inner rectangle would cut right through rather then being a stencil if that makes sense.
 

A simple rectangle only takes about 3 min to cut. There is something going on when I create the path difference to generate the rectangle that appears to be hollow with a thicker border.  

I'd remove the fill from the inner shape(s) and make the stroke .5mm. 

Thanks @TylerDurden, that does not work. This is where I started, however Beam Studio does not recognize stroke. I could make the stroke 20mm and it would still cut a line about 0.2mm thick. The only way I can get it to cut a line to a specific thickness is to use shapes. Hence using the above process to make a shape that appears to have an 0.5mm “outline”. It could be that Beam Studio just can’t figure it out so is not the file that is the problem. I have tried converting to PNG and whilst it speeds it up, it still takes well over an hour to cut. The mystery continues! 

I understand.

The path is over 59cm long... how fast is the laser moving?

I like the measurement dialogue box! How did you get that to come up? Sorry for the semi-novice question :)

The laser is moving at 4mm/s. Whilst that is less than 3 mins total, the inner rectangle being 0.5mm requires a few passes. It should therefore take maybe 5 mins in total. 

Measure Path is one of many many extensions that help make Inkscape versatile and powerful.

BTW... does Beam Studio recognize rectangle objects? I'd try converting the large rectangle to a path. 

A fair number of CNC type machines only understand path data, not svg geometric primitives. 

Very nice, I did not know about the Measure Path extension! Thanks :)

Yes Beam Studio does recognize rectangles. I did convert both the large and small rectangles to a path, however still is saying 3 hrs 40 mins to cut :(

I got an error warning about SVG1.1 when loading your file or any Inkscape/Affinity Designer SVG.

It says here 45min for 3mm wood cutting on your file - which I find still too long. 

When I take all as Strokes I got this:

So my guess it´s the color filled shape that´s the culprit. If you want a larger gap than the lasers diameter give the shape a stroke and no fill - an outline so to speak:

Thanks @Polygon, much appreciated. I did try stroke at the beginning of this process and it did not work (would not cut the line width correctly). I am however encouraged by your screenshots. I will try it again!