

No, the article says it’s going to the King’s estate, i.e. the crown, not to the privy purse, i.e. Charles’ pocket.
Is some of it being used that will ultimately benefit him? Probably. But according to the article, the policy governing this says any benefit to the king himself should be merely incidental.
This article does not appear to allege that they are violating that policy.
You should consider opnsense instead of pfsense in any case.