option to disable the <div class="optiscroll-h"> markup

[neuropass]

is there a way to tell optiscroll not to inject the horizontal markup?

<div class="optiscroll-h"><b class="optiscroll-htrack"></b></div>

or vice-versa in the only horizontal is used.

basically inject only what's in use.

[albertogasparin]

No, given they are just two elements, I considered add/removing them on scroll change more expensive than leaving them always in the dom.
If you are having issue with styling, you can force display: none on optiscroll-h and then override it when has-vtrack has-htrack classes are added to optiscroll main element (instead of the default visibility: hidden behaviour).