% btc to share between cold storage and exchanges with earning options

Good afternoon all,

I am quite new to bitcoin (a year now) and it is actually the first time I am writing something on Reddit. I did some research, I am using a cold wallet and try to dca a small amount on btc only and I just start using LN on a non custodial mobile wallet.

I already went through similar subjects but my main issue is not the fear of losing access to my cold wallet but more a risk analysis to allocate a small pourcentage to an exchange to earn interests (Ftx 8% or Binance 5% apy on btc for example). I was thinking to allocate 90% on a cold wallet and 10% on exchanges. What do you think of this in a long term investment plan, is it too much/not enough ? I truly understand the concept of not your key not your crypto and the risk of exchanges but I try to dertermine a correct risk/reward balance (even if at the end I only invest a small amount that I can afford myself to loose).

Thank you for your thoughts on this.