The conversion to a permanent policy provision is useful if you want to insure your underwriting status as of today. So for example, if you get underwritten as super preferred, but in 20 years your health deteriorates, or god-forbid your disabled in a car accident, you might find you need some permanent insurance, and this provision would let you get a permanent policy at super preferred rates. It's so cheap (an extra $3 a month?) I'd probably get it.
The term extension is kinda not as valuable in my mind, because if you need insurance still in 20 years you probably want a permanent policy. and if your healthy, just go out and get a new policy. However, one subtle note is that the contestability period and suicide exclusion period will start over with newly underwritten policy. If you exercise a conversion/extension provision, those shouldn't start over.
I understand you most likely won't use those provisions, but only you can answer if insuring your underwriting status is worth the $3 a month.