Hey Adolfo - Nice work - you probably already went through this exhaustive thread too 
good that you’ve gone with the sqround pack format!
as for PLA - there are as many cons as there are pros I’m afraid and it’s really not an ideal solution for long shelf life packs like Huel. honestly it has no real world benefits over a 100% rPET bottle. it’s true you’re not burning huge amounts of fossil fuels to create it but the same is also true of rPET. You also have a lot of complications with it in the recycling circular chain.
As with all things recycling - there really is no magic silver bullet material at the moment so we have to make the best decisions we can on balance for the time being