Firos divisible amount

Hi,

I was buying and selling and i notice Firo is only divisible by a minimum of 0.2 on Binance.
Why?

Another coin is Beam… There is no 0.1 beam. Only 1 beam.

I would expect Binance does this based on price. Firo you can buy there with smallest unit of 0.1 Firo.

It would not make much sense to buy 0.3 of Beam or Shiba, but it is reasonable to buy for example 0.3 of BTC which has much higher purchase value then 0.3 of Beam.