I like that tester shown in post 17...
This is the one I have, it is ok....

Yes I have one of the adjustable ones I forget just were i had it set now but it was pretty wide i want to say it was set to 45000 but it'* got a mean blue fire that jumps even further then that I have had several coils that I swapped out and now has 3 new ones and a new ICM on it just because I wanted to be sure it wasn't the issue. Yeah this issue has made me a parts changer why because I cant figure it out lol seems I've tested everything at least twice.

Forgive me for asking if you mentioned this before, but have you done a compression test on all cylinders?

When it is misfiring, can you get to the tailpipe and sniff it a little?
If you smell raw gas the injector could be stuck open...
Try to see if it smells like raw gas, or sulfur...

Have you tested the fuel pressure regulator to make sure gas is not coming back through the diaphragm?

Has the MAF been cleaned, or looked at on a scanner to see how well it is running?

First off thank you for your interest. Yes I ran compression tests on all cylinders I believe my results are in my first post. I can't smell raw gas at exhaust but it'* not a dead miss only ever few seconds now that I found the vacuum leak at the fuel injector o ring and fixed it. I have tested fuel pressure leak down it holds up over a long period. There is no fuel leak from the fuel pressure regulator vacuum port not even the smell of gas on that vacuum hose that plugs in there. I cleaned the maf sensor then replaced it whatched only a slight difference in fuel trims difference from one to the other mafs.

Very welcome, sorry I did not hit on anything you have not tried already, sounds like you are covering everything that I can think of.
I had a 96 Park Ave or like 15 years, they are great cars, so I really hope you can figure out the issue and fix it!

Thank you .

ICM conection
found this after car would not run at all last week it looked worse before I cleaned it. That'* were the 12 volts comes into the ICM I couldn't see a 3x off the crank sensor and intermittent 18x I thought that was the problem after replacing the the crank sensor with no success I found this. Tried to clean it up without any luck I replaced it with one off my wrecked Buick. It'* running again but still have the #1 misfire at Idle.

Has the intake gasket been done?

Yes I know this a long post but it'* in there somewhere lol