As I said before, you have to make extra styles for content used in Articles, it will be best universal solution. I do it for my projects as well, so I can set different for bigger and smaller phone.
Of course you can do that manually in each addon... but after 60 min of doing it you will be tired.
Small tip, for content used in Text addon in Article:
@media screen and (max-width: 680px) {
.article-details-content .sppb-addon-text-block h2 { .... }
.article-details-content .sppb-addon-text-block h3 { .... }
.article-details-content .sppb-addon-text-block h4 { .... }
}
@media screen and (max-width: 540px) {
.article-details-content .sppb-addon-text-block h2 { .... }
.article-details-content .sppb-addon-text-block h3 { .... }
.article-details-content .sppb-addon-text-block h4 { .... }
}