Daksh Dogra

Yes, please DO NOT remove portal chunkloading as in contraptions its the only thing which helps to reduce lag, and the only control over chunk loading. With this, one will need more loaders and if you have made this change to reduce lag, then this is not going as you have planned. Mob Switches will just be very laggy as Druser  pointed and add unnecessary lag to the game and will prevent big contraptions from working without lag as they used to. Making this an intended change will just frustrate the Tech community as useful things are removed like the hopper chunk loading in 1.12

Thank you! I think you can close the issue

So I should just place torches on the sides and it will disable them from spawning completely?

And the only way I could disable it was to place lava on top of the spawner and all sides with blocks to prevent skeletons frm spawning

the file is quite big I could not upload it here

It will show that there were no holes what so ever and that the skeletons were spawning frm the spawner.

https://imgur.com/gallery/Ri3S5cu

here is the link of the replay mod view

ok I will provide a replay mod view of it

http://www.mediafire.com/file/ez01oro4qgndspr/Minecraft_1.16.4-Multiplayer%25283rd-party_Server%2529_2020-12-06_16-39-35.mp4/file here it is

I will upload the video. I am having some issues