Why instant unstake is not available via bemo?

Instant unstake is not possible through bemo because, at the time of the request, the TON tokens are in the validator pool, supporting the blockchain. Until the current validation round is complete, the funds are unavailable for withdrawal.

To avoid waiting, users can sell stTON on an exchange at the market price, considering the commission. 

To exchange stTON for TON at the fundamental price, use the Unstake function in the bemo app.