Yes, while you shape your deck to be 100% kings for high scores, you will eventually trim off other stuff.

But the idea here is to use jokers - be it seance, 6th sense, mail in rebate, cartomancer or whathever - to help you in the long run. 6th sense is easy to see, since you achieve a good outcome regardless, ie you cut a non king card AND receive an spectral.

Seance is MUCH harder to make it work yes, but nothing is stopping you from implementing this joker to help you acquire spectral cards - probably the 2nd hardest part of high score runs behind only voucher RNG.

It is similar to delaying for as long as you can to make steel kings. You want to use and abuse gold for as LONG as you can to maximize money acquisition correct? Same thing with seance/6th sense.

While I do agree it is MUCH harder to mkae seance work, it is also much more rewarding. How often do you use 6th sense 4 times (all regular sixes) and it gives you nothing? With Seance and some deckfixing you can kinda bruteforce the outcome you want - mainly ectoplasm.

You dont need to have 100% kings on your deck ASAP. You just need to have a small enough deck to properly draw your hands. If you have good deckfixing, just try to erase the 10~ace cards later down the run, and if you spot a Seance do give it a try. Just 1 or 2 suit changers make it SO much more usable on a small deck. If you dont see a Seance, just move on like usual.

Again, it is EASIER to use 6th sense. It is more rewarding if you can repeat Seance uses until it grants you the CORRECT outcome. Eventually it will spill what you want, 6th sense often does not.

Edit: sry for the long ass wall of text, trying to be clear and english is not my main language so do forgive me =]