Make blocks a part of the UI instead of blocks in the hot bar.
There are many situations where players have exploited the blocks to either get out of bounds or catch hiders who have jumped into an area using parkour. I think that the new UI could be around the corner be next to the timer or above the energy level in the seeker UI. The UI could also have the icon or emoji of the block. The UI should continue to cycle through like normal, and should still say “3x Oak Leaves” when having the items held.
Alternatively, a new menu could be developed in place of the blocks. It would pop up a UI of all the hider blocks available at the cost of the seeker not being able to move for a few seconds.
I think that this could be beneficial to make hiding and seeking more fair.
Image below for idea where new UI could be