We had lots of problems with invalid translations in the past because translators messed up placeholders. That lead to broken builds and lots of support requests and I really don’t want to switch this back to warning.
Unfortunately there’s only one check (“Variable substitution specifiers (like “%{var}”) are preserved in the translations.”), otherwise I’d exclude the %{count} variable from this check.
The following offer still stands:
Of course that won’t work if this problem affects lots of translations.