Extensive homepage redesign in Journal - do I need to clear system cache?

Opencart 2.3.0.2 and Journal 2

Made some extensive design changes via Journal features a couple of weeks ago to the main homepage of our website.

Just a few days ago realized that only on SOME mobile phones, the add to cart button doesn't respond and the page alignment is a bit weird (add to cart at bottom under the description when it should be at top after image).

Found that in most cases by clearing phone browser cache this fixed the issue.

While the changes made were focused on the site homepage, would it be important and good practice to clear the Opencart cache in addition to the Journal cache after having made such changes? (we did clear Journal cache, but are not typically in the habit of clearing opencart cache).

Thinking since it seems cache related that clearing the Opencart cache would probably resolve any remaining phone users experiencing the issue.

How do I clear the Opencart Cache?

Do I delete all files in the opencart system/storage/cache directory (except the index.html) via FTP and delete? Makes me a little nervous to do so. Is that a harmless thing to do?

Thanks in advance for any insight.

Well, you obviously only need to come here, if you need someone else, to assist.
Otherwise, you really don't seem to care much about this place, after beeing around so
long already. And you would also be aware of the fact, that Journal-related matters
belong to the Journal Support Site, since this Theme is neither offered nor sold
by OpenCart.
Sorry, but I could not resist, after looking at the amount of postings you made so far ...
Good Luck !
Ernie

Wow. OK then. Thanks for your kind help.

You are using a non-standard compliant web theme. Normally all that is required to clear the caches are these steps:

Dashboard > Developer Settings (icon top right top) > Refresh Theme and Refresh SASS
Extensions > Modifications > Refresh

The OpenCart caching strategy is bad enough, for a web theme to introduce another cache layer is just plain bad.

If after clearing the caches you still experience the issue, then it might be time to install a proper, standard-compliant web theme which uses the responsive bootstrap-based layout correctly. Or you will have to ask the authors of Journal for support.