Adjusting fade transition speed for galleries in 7.1

Ridiculous that I can't adjust the transition speed for a gallery in 7.1!. Seems so basic. The fade transition is so fast that it's hardly noticeable. If it's a full screen slider, this is highly annoying – too abrupt! Just contacted help and it's not possible. Every free JS slider plugin out there has that option. Really? 

Hi. Have you found the solution yet?

Any fix on this?

can we get any solution for this issue?

cant seem to find anything related to adjusting transition speed for gallery slideshow

the code that I found in squarespace forum doesn't work (it only works for few slides, very inconsistent)

.gallery-fullscreen-slideshow-item-img{
    transition: opacity 1600ms ease-in-out !important;
    -webkit-transition: opacity 1600ms ease-in-out !important;
    -ms-transition: opacity 1600ms ease-in-out !important;
    -moz-transition: opacity 1600ms ease-in-out !important;
    -o-transition: opacity 1600ms ease-in-out !important;
}

//.gallery-fullscreen-slideshow[data-transition="fade"] 
.gallery-fullscreen-slideshow-item[data-active="true"] .gallery-fullscreen-slideshow-item-src{
    transition: opacity 1400ms ease-in-out !important;
    -webkit-transition: opacity 1400ms ease-in-out !important;
    -ms-transition: opacity 1400ms ease-in-out !important;
    -moz-transition: opacity 1400ms ease-in-out !important;
    -o-transition: opacity 1400ms ease-in-out !important;
} 

I am crying for help..