Hi ulfr. The list of names of the main packages that are in the dCorePlus-stretch.sce.lst file in /tmp/builtin is below:
tce-setdrive
xorg-all
wireless
flwm_topside
b43-fwcutter
dosfstools
iw
wireless-4.8.17-tinycore
ndiswrapper-modules-4.8.17-tinycore
aterm
ndiswrapper-utils-1.9
ndiswrapper
Use sce-import to import each one individually, or you can separate their names into 2 or more lists if you want, to make 2 or more SCE extensions out of the entire list.
If they are located in /tmp/builtin, they would be automatically loaded.