Variants option(s) on all product cards is an advanced customization that will vary wildly between themes.
Not advised for new online merchants to cram more into less.
If you have a simple theme don’t try and complicate it.
It can be saner to start with quickview feature if you are testing collection page conversion methods.
Trying to cram more into less in the hopes of increasing conversions or some other factor without actual data or experience to back it up is not a good plan. Unless you have the development budget to back it up as a possibly failed experiment that burns money then cramming an entire set of a variants options into a small UI is not a good plan.
In the wild you mostly you only see single options such as colors surfaced in such area as very simple color-swatches that then adds just 1 product to the cart with no qty input. Or a quickview UI.
If you do need to pursue either approaches you can contact me, info in sig.
