My save is down to 95MB. Looks like it worked for me.

It is no bug. Only half of the modules effect is transmitted.

https://wiki.factorio.com/Beacon
A beacon's effect transmitted is only half of the effect of the modules within. So, two of the same module = one module's worth transmitted.

Same with speed modules.

Thank you for your fast work

After biters are killed and I continue playing, after a while the file size is again rising fast.

Thanks.

Indeed there is a problem with the biters. If I kil all biters by command the file size drops to 115MB. If I set the world to peaceful afterwards there is no additional loss.

Sry, didn't see option to create a link.
save file: https://we.tl/t-H87yMCUULg
screenshots: https://we.tl/t-jF1LzxnBGX

Hello guys. I have a map started for 0.17. now played over 150h. The map is not very large comapared to my others. But this save file (.zip) is over 500MB. In fact it is so big, I have problems saving and loading this map. First the screen freezes and than it takes around one minute for the saving (...