I'm not an expert on
Yucca plants, and there may be
different varieties.
Had these growing in a section of my flower bed, for well over 25 years. They did not multiply or spread very much during that time. I then redid my flower bed (5 or 6 years ago) and moved them to other end. Dug up and replanted. I think that for a year or two there were no flowers. Then things went back to normal. In their new spot they are doing same, NOT SPREADING. The new growth seem to be coming out of the roots. There are seeds, but I never tried to plant them. They would just fall to the ground. If these were very prolific, then those seeds would overtake that flower bed.

It just has not happened with mine. I will try this autumn to take and plant some of those seeds in a different flower bed, and see if they sprout.
Sounds like your blueberries are the "low bush variety" They are also referred to as "BILBERRIES" One way to easily check is to cut a berry in half. If the flesh is blue, then they are the Bilberries. If the flesh is grayish, and only the skin is blue, they are the High Bush common variety. Used to go picking them at an orchard in Michigan. Bushes were as tall as me.
My BFF that lives north of you in Ashland Wisconsin goes picking for wild blueberries (bilberries) in the North Woods.
My intention is to get a few of those small bushes and container grow them in large pots.