Yes, once this visa is issued, it is a 5 year multientry visa regardless of the length of the program you are approved for.
The idea would be to encourage you to return again over the 5 yrs.
The only exception is that if you intend to do an incountry extension, you will have to qualify again for finances and possibly courses, (that is unseen yet).
As well as the extension fee of 10k.
It would make no sense to extend in country, just leave and reenter requires nothing.
If you qualify get it NOW before they tighten the qualifications.
In the case of asking for finances for dependant I would recommend uploading the primary person's bank statement or you could try creating a photo that says not applicable.
This works with non-o visas when they are asking for things that don't apply.
OR contact the embassy directly on how they want to see it.