I don't have SDE, I just have Silhouette Studio and recently they had an upgrade for the software which also removed the cardstock options settings-here's their reply:
Thank you for your inquiry. We are sorry for any frustration caused from the change in pre-set media types in the Silhouette Studio program. The latest version does include a reworked list of media types as they pertain to our company’s products offered. There have also been some previous media types adjusted to accommodate and apply to the “thickest common denominator” for similar material types that fall within the same family of materials.
If you have a new media type and want to create your own setting for further future reference, you may do so by clicking on the plus sign in the list of material types. You may then enter in the desired setting values. The new material type will remain in your "User Defined" section at the top of the list of materials avaialble.
In order to find the right settings for any specific material type we would highly recommend using the “Test Cut” feature in the Silhouette Studio software program. You may go to the “Silhouette Cut Settings” option located in the upper right-hand corner of your software screen. This will bring you to the screen w here you may adjust your media type and use a test cut feature found at the bottom of the panel. This will allow you to move the blade over your material and then try out your settings to cut a very small square and triangle. This helps you to know if the selected settings are correct for your material type of if you may need to select a different media type setting or manually adjust the “thickness” setting .
In regard to the blade and finding the correct settings, there are two things to take into consideration: a) the blade level and b) the “thickness” setting.
The blade level controls how far the blade is exposed in 0.1 mm increments. This accommodates for how thick the material is. For example, a blade level of 1 = .01 mm, a level of 2 = 0.2 mm, etc. If you have a material such as cardstock where the actual thickness is 0.3 mm (as is most cardstock), setting the blade to a higher exposure (such as 0.6 mm or setting of 6) would mean you are exposing the blade beyond the actual depth of the material. This does not allow the blade to cut better. It just exposes more of the blade and if extending beyond the actual thickness of the material can wear down the blade tip very quickly and result in ragged cutting results. From that point on, you would then have to expose the blade to a higher level because a setting of 6 would actually be only exposed 0.3 mm since you had worn down the excess tip beyond the material’s thickness. We would thus discourage you from attempts to overexpose the blade to try and get a “better” cut.
The “thickness” setting from the software controls how hard the blade is pressing down. This accommodates for how dense the material may be. For example, a sheet of paper that measures a thickness of 0.3 versus a sheet of dense cardstock that measures a thickness of the same 0.3 depth would require the blade to be pushed down with different thickness levels.
If you feel that the material in question may be slightly deeper than the recommended blade setting recommendation, we would recommend that as you raise the blade level, you also in turn lower the “thickness” setting in the software so that the blade if overexposed is not still being pressed down with the hardest force possible and potentially breaking the tip. You may then increase the “thickness” according to further test results.
So I guess their biggest reason for changing the settings is to accommodate their specific media.