I would like to be able to optimize place&route for a single partition at one time. Documentation refers to this capability, for example:
Example 1: Optimizing a Timing-critical Partition
After performing a lengthy full compilation of a design with multiple partitions, the Timing Analyzer reports that the clock timing requirement is not met for a specific design partition.
You apply optimization techniques to the specific partition, such as raising the Placement Effort Multiplier option value. Because Placement Effort Multiplier optimization of the entire design requires significant compilation time, you can apply the optimization only to the partition in question.
This is from the Quartus Prime Pro Edition User Guide: Block-Based Design (https://www.intel.com/content/www/us/en/programmable/documentation/yrh1513988099640.html)
I have seen other references to this idea, but I have found nothing in the documentation that explains, for example, how to set Placement Effort Multiplier for a particular partition (it seems to apply globally across the design).
Is there a way to do this or am I tilting at windmills?
I am afraid it is not feasible to apply that based on a specific entity/hierarchy. You can however, perform timing overconstraints to instruct the Fitter to focus on certain blocks within the same clock domain.
You can refer to 2.2.9. Using Fitter Overconstraints in the User Guide
Let me know if you have problem on this and I'd be glad to assist you