You can’t. Due the formulas and unique names for points it makes it a difficult a task to achieve. Importing one pattern into another is likely to cause collison between the point names, which would have to be changed and resolved in the tools & formulas.
The only way this would ever work is if we devise a point naming scheme for specific darft blocks where all the points would have a unique name. For example… all collars might be designated with points begining with “C”, all sleeves with “S”, pockets with “P”… etc.