Custom "Read More" Text for Block Template "Email card: Summary horizontal"

I came across the block template "Email card: Summary horizontal" (among

a few other Core email block templates) that don't support custom "Read

More" text.

I needed this feature for moving an obits newsletter from Zen to Flex, the text for the custom block template on Zen was " View Obituary / Sign Guestbook," which is more sensitive and empathetic than "Read More" I would imagine there are other use cases for this as well.

However, I did notice that the Core block template uses the macro email_assetLead in the Core Flex Email component.

Blocks using that macro can use "read_more_text" as a custom property to

support custom text.

I made a custom copy of the Core block template "Email card: Summary

horizontal" for now, but of course it'd be nice to have this in Core.