First gun - thoughts on no rear iron sight?

Got a G17.5 a month ago. Non MOS because I didn't know any better. Then I decided I wanted an optic, so here I am with Wager Machine Works milling the slide (fantastic job) within 7 days! Only problem is, I didn't know any better (again) and did not opt for the dovetail in front of the optic for the rear iron sight. What should I do? Do I really need it? I know people will say I should always have a backup in case the optic fails, but aren't these things virtually indestructible?

Got a G17.5 a month ago. Non MOS because I didn't know any better. Then I decided I wanted an optic, so here I am with Wager Machine Works milling the slide (fantastic job) within 7 days! Only problem is, I didn't know any better (again) and did not opt for the dovetail in front of the optic for the rear iron sight. What should I do? Do I really need it? I know people will say I should always have a backup in case the optic fails, but aren't these things virtually indestructible?