For a long time ago, exists bug with cf-promises evaluation.
When I try to set a big scope of classes, cf-promises try to evaluate policy before execution, but make it Indefinitely or very long. When cf-promises finish evaluation, cf-agent execute policy in the twinkling of an eye.
It was reproduced on all versions >= 3.5.0 (older version I did not testing)
EDIT by jimis: The slowdown is seen in the attached debug.log, right after the string debug: Evaluating vars promise: integers. In a normal debug run, cf-promises just sits and waits after that line seemingly doing nothing. The huge list of ExpandScalar() lines that follow are printed here because of --log-modules=all.