and here is a small cut from the video i captured trimmed down and low quality but i think it should show the self corrections i had before rebuilding trap.
end of snapshots are time stamps from video (real world time). in first shot(2.44.55) i am at Y80 with a light lvl of 15. in fifth shot(2.47.07) i am at Y83 now with a light level of 6. last two shots (2.50.13 and 2.50.25) i am on same block within seconds of eachother. block lighting update visible on video. Can upload it to my youtube if you would like to see full footage.
edit: forgot to add- first 3 shots are with faithfulvenom32 texture pack. rest are with default pack.
As previously stated, the issue was when there were No pistons as part of the design. That being said, even if there were pistons the whole area was encased in dirt so the piston transparency would have nothing to do with it. The issue resolved once i Added the pistons and redstone repeaters. Hence my thought that the regular lighting updates from the repeaters has actually fixed the issue. I will take screen captures once my video editing software is finished with it's present rendering job. The issue does not seem to be happening in game any longer as far as i can tell.
At this point i can not recreate the issue. tried making another box the same size on top of the original one(with optifine and without)but does not occur again, and original glitch was fixed when i redeisigned the trap so i can not check it with optifine removed. it did originally occur without rei's minimap installed (loaded that after i had built the trap. is not something i ususally have loaded). i will update if i have it happen again.