Maybe it’s best to do it outside of openlane and make a mini TCL script for OpenSTA? Something like:

read_liberty example1_slow.lib
read_verilog example1.v
link_design top
read_sdf example1.sdf
read_spef example1.spef
set_data_check -fall_from X1.Y -to X1.A -hold $H
report_checks

And it will measure the delay and compare against the hold requirement. This way I can be sure is at least $H long, and also get the prediction from the log.