Hi Jurgen,
hybrid scenarios are typically used to report on a slice of the original scenario's data in order to improve reporting performance. There are other use cases too, of course.
If you need the target scenario data to be edited, then you cannot use the Share Data option.
Not sure what "quite a while" means, but the duration of a force calculate depends on many factors. First I would recommend limiting the members you actually copy to the destination scenario to only those needed. E.g. only the revenue account and UD3-UD8 Top to None (if applicable, depending on your individual requirements). That reduces the amount of data copied to the target scenario and therefor also the amount of data calculated in it.
You can also set the ExecuteCopyDuringCalc to False as shown in the Design and Reference Guide section on Hybrid Scenarios and execute the copy from a data management step. Then only the copy is executed and not all of the other calculations that are active for the chosen scenario type. That approach is usually chosen as one does not always need to copy all data during each calculation (as you already know).
There is not always an answer that I can provide as to what is the best in a general sense as it always depends on the exact requirements. But limiting the copied data and using a data management step for the copy seem like appropriate first steps.
If you want to use the 'Share' path, you could also set up a dynamic member (e.g. in UD8) displaying the data from your source scenario plus the adjustments that the users enter on a specific adjustment member (e.g. also in UD8) in the target scenario. That would no longer use the Hybrid scenario settings but would eliminate the need to copy the source data. As I do not know your data model, I cannot assess if this suggestion fits in your case. But it is easily set up and you should be able to test it without much effort.
JackLacava
