This law (and other recent CA YIMBY laws) don't create much surface area to sue or slow a project:

* The approvals are designed to be "ministerial", meaning there is no discretion on whether to approve or not. If the project meets the objective criteria spelled out in the law, it must be approved.

* If the city doesn't approve in a limited time window, it's deemed "approved" by default.

* Ministerial approval protects the project from CEQA lawsuits. CEQA requires the government to consider the environment when making decisions. When the approval is ministerial, the government doesn't make any decisions, so there is no CEQA process to sue against.