Sorry for my late reply. You are right, I can recreate this and will fix it for the next update. It works if it is changed globally in the template settings.
Until the fix is available, you can save your adjustments under “ASA2 / Service / Custom Frontend CSS”, e.g. like this:
body.postid-123 .asa2_horizontal_box .features {
font-size: 50% !important;
}
This adjustment would only affect Post ID 123. Alternatively, you can select individual products only by using the unique ID that ASA2 gives to each product displayed which can be found in the uppermost surrounding container.
I hope I was able to help you. If you still have questions, please let me know.