8 – Use a custom field as a subfield in another custom field

I published a while ago and now I have successfully implemented a custom field (this was an extension of the DateRange field type to add control over the presentation, etc.)

I have some other use cases where I could have a modified date range field as a subfield in another type of custom field, now I know that I could implement it in the same way in each new type of custom field, however, it would be a lot more simple if I could place my custom date field. If this is not possible, is it better to make my custom date the base type and extend this for each type of field I need to create? Or is there another solution (I don't want to use paragraphs since I can't get the degree of customization I want)