I think with Persuasive 297 you're better off gaining Emetic Revelation from Sell lightbulbs to Londoners rather than The Spider Symposium. 250 lightbulbs can be purchased using 45 Khaganian coins costing 1 action when the time is False-dawn to Midday or you can buy them directly from the Midnight Market at 20 moonpearls per piece (+100% markup but no additional action cost). Khaganian coins can be obtained from the Black loop and conveniently it shares a node with the White loop so it's easy to switch from one to the other. Even though it costs Emetic Revelations you should still have a comfortable net gain for a self-sustaining cycle. The other route is grinding moonpearls through The Stacks which apparently it's viable to get 40 roof-charts and sell them for 10120 moon pearls in about 20 actions? That is equal to about 500 lightbulbs in 20 actions. This should be worse than the coins but from my rough calculations they both should be better than the Spider Symposium route. Another way is to procure extra Revelations from the Engineer when the items required can be efficiently obtained but not sure which one is the best. Maybe Correspondence Plaque since you can buy Maniac's Prayer from the Rat Market at value then up-convert it in bulk.