#1: Yes. However, it is a little bit tricky, since you can use the button in multiple ways (not only shortcode, but also directly as element). Would require a settings page, so it is up to the user. This way, we can get it optimized. Put it on the roadmap. Thanks for the input!
#2: I would argue against this. In case you are using an iPhone with Chrome, Safari is also available to you. So, hiding options, just because they are not working on Chrome, could easily lead to the button being of no use at all. Imagine a case, where the admin defines the apple option only. In this case, following your proposal, we would need to hide the button completely on Chrome. At the moment, we are telling the user that he can simply switch to Safari and paste the content of his clipboard (where we automatically already stored everything). This way, the process is still operational.
Of course, this is not ideal. We are working on a hosted version, where at least the ics download functionality receives better browser support. But this will take some more months and event with this, there are many fallback situations left, where Big Tech is not playing nicely.
Anyway, for the current concept/product, it makes more sense to inform the user about his options instead of showing nothing.