Besides, how that "BLOCK the "update the roulette for 10 seconds if some player spinned then" would solve the "someone refreshed the wheel with that Oasis (or whatever) still available"?
Time = 0 : Player 1 spins, get coins not the "special" he/she wants. *** wheel refresh blocked until Time =10 ***
Time = 1 Nobody in the hood spinned.
Time = 2 : Player 1 spins again, wins a Fast unit, not the special he/she wants. *** wheel refresh blocked until Time =12 ***
Time = 3 : Player 2 spins, wins a decoration *** wheel refresh blocked until Time =13 ***
Time = 4 : Player 3 spins, wins one of the 4 "specials" Player 1 wants. *** wheel refresh blocked until Time =14 ***
Time = 5: Player 1 is distracted by collections ready at the city, or noticing a building just plundered.
Time = 6: Player 4 spins, wins a fast unit. *** wheel refresh blocked until Time =16 ***
Time = 7: Player 3 spins, gain another "special", lady luck is with him/her today. *** wheel refresh blocked until Time =17 ***
Time = 8: Player 5 spins, wins some medals. *** wheel refresh blocked until Time =18 ***
Time = 9: Player 2 spins again, wins the 3rd "special" *** wheel refresh blocked until Time =19 ***
Time = 10 to 18: No one spinned, maybe everyone is waiting for others to get the low rewards to increase their chance to get the last special. or just busy at the city or battle fields.
Time = 19: *** Wheel Refresh unlocked*** Player 3 is not interested in the 4th and last "special", he/she already won 2 today, got 8 already at the city plus, another few at inventory, therefore refreshes the wheel feeling lucky to get something else/ something better.
Time = 20: Player 1 feels irritated because someone (Player 3) refreshed the wheel with one "special" still available.