Be honest with yourself for a moment, if you invested the 40k into crypto, what would you do if you woke up the next morning and your 40k had suddenly turned into 25k? If you're answer is panic, then you shouldn't invest in crypto because I 100% guarantee you that at some point you WILL lose 20-50% or more of your value in a 24 hour period. While I firmly believe in crypto and how various layer 1 protocols will transform how businesses operate, and that the 1-5 year price outlook is fantastic, that doesn't mean that in the short term its not soul crushing to see your portfolio balance fluctuate by hundreds of thousands of dollars on a near daily basis. Many people say they would stick it out and not panic sell during a market crash, but trust me when the crash actually happens, you're going to start second guessing your decisions.
Repaying the MBA loan is pointless. Even something as simple as lending out crypto stable coins to providers like Nexo, Celcius, Crypto.com, Anchor protocol, or others, can earn you a pretty risk free 8-20% return on your money. Why repay a ~5% interest loan when you could safely earn 8-20% instead and profit from the arbitrage? With the rise of DeFi, banks are obsolete dinosaurs for thinking that people would be content to earn 0.01% interest on their deposits.
Personally I make more money with crypto than I do with real estate, but the only reason I feel confident investing in crypto as heavily as I do is because I have other stable investments like my real estate that allows me to take much riskier bets on volatile assets like crypto.