“Connection lines” instead of “Connection points” in VISIO

I wonder if this is possible:

Make a line or the whole perimeter of a figure "Connectable" in VISIO. ie, Not connection points but connection lines. (or say, a line full of connection points)

Plus, if needed, lock the intersection point at the current relative position or a relative range, and release from lock when later mind changed.

update: Just found out, if a figure doesn't have any connection points, then it will connect direct to the line instead.
But I want to keep the basic connection points, yet can still to choose whether a new line auto-connect to near connection points or just connect to the line's nearest intersection, and better yet to lock intersection at the relative point. — Is this possible?

Thanks!