Hi,
It should be easy to disable the comparison system for low resolutions by just hiding the compare button on the listings for low resolutions:
@media (max-width:900px) {
.hikashop_compare_button { display: none; }
}
The problem with providing a generic solution is that the template, the modules and even the width of the images of the products will be different for different websites and thus it's hard to set a defined width upon which HikaShop should reduce the number of products allowed for the comparison.
Furthermore, HikaShop doesn't necessarily know if the width available on the comparison page will be the same than the width available on the products listing where the compare buttons are. For example, it's quite easy to display a filter module on the left side of the products listing, and not have it on the comparison page. But the comparison system on the products listing has not way of knowing that and thus can't guess the width available on the comparison page to calculate the number of products allowed.