Mafia City - you can actually have 2 build queues running

The VIP store stocks 10x 8hr 2nd build queue, restocks every 7 days. You can access it by clicking the upside down silver triangle in the VIP section.

I have spent a week on single build queue before finding this xd

Edit: the game can be found for $20 on ayet during 2x SB promo and lootably on other GPT sites. Requires lv20 mansion in 40 days, but with the 2nd build queue can be done in 2 weeks