The tooling has improved, wp i18n
can now handle all the i18n-related tasks, including Blade-PHP
template files.
Please take a look at this discussion/guide about using the new wp i18n
for scanning/updating and compiling gettext and JSON translation files:
Related PRs (Sage 10):
https://github.com/roots/sage/pull/3081
https://github.com/roots/sage/pull/3076
The same can be used for Sage 9 themes. Just the input-path needs an adjustment.