Have you considered applying for conservatoires abroad? Unlike in Spain, there's no tution in many countries (like here in the Czech Republic), or students even get paid for studying (like in Denmark). Language shall not be a barrier in case of conservatory (not like if he was to become a lawyer for instance), and the mere experience of spending few years abroad could be even more valuable than the diploma.
There is definitely an idea to go abroad for at least one year (Erasmus), maybe when he will be in the third year. Or later, for the master's if he does well and wants to continue. In February he spent one week in Germany in an intensive orchestra project and it was great. Also, he saw the level and way how musicians work and practice there hahaha, so there are things where he has to improve first lol 😁
The state conservatoires that we visited don't have tuition either (just the enrolment fee and maybe the exams). Well, I hope that no surprises will arise in the meantime 😂 apart from all the other expenses that this studying phase will bring lol
Fingers crossed :)