I need a bra all the time now.
Without one, I sag, wobble and ache, and it's a real relief to fasten that back band, slip up the straps and swoop & scoop the girls into the cups!
I have never got into bra band extenders, though.
Partly because if you are using an extender, then the bra fit is probably wrong. Your bra band needs to be very firm, as it is mainly the band which supports you. My "go to" bras have bands which were suffocatingly tight in the fitting room.
Many bras for small cup sizes only have 2 hook fastenings. Look for bras with a 3 hook fastening band. These bras offer wider side panels and much more sympathetic support and lift, and often, wider straps.
Secondly, extenders widen the bra strap rear support locations, so your bra straps are more likely to slip down. I hate to lose a bra strap, but I see so many women with dropped straps, that they must be wearing the wrong bra sizes.