If you block development for X number of years and it turns out you had no grounds to do so, you need to compensate the developer (or even more broadly - damage your opposition to the project incurred to the common good)
that could stay, but make them prepare the assessment.
also the whole problem is that the timelines are ridiculous.
there's no need to create a report that goes over 99.999% of the whole problem space.
do a 95% job, check for the past fuckups (ie. are we literally trying to pave over homes of disadvantaged communities? are we promising very fair compensation for this but then just scam them and leave them with some half-assed dilapidated boarding house on the outskirts of town? are we willfully ignoring some group with real data?)
it can even go to court, but make it quick. have a standing tribunal for this and they should be bound by law to decide whether the claim has enough merit to proceed based on 1-2 weeks of examination.
simply put there are not enough standardized and well structured parts of this bureaucratic pipeline. (and there should be very very few non-standard parts. and standard parts should be quick and transparent to evaluate.)