@Enemal
I'm sorry for replying to your message so late. The compatibility description for this mod has been added to the mod description. Additionally, I'm not the author of this mod and currently I'm unable to fix the compatibility issues with other UImods. I'm so sorry.

In the original description there's this:
Build 42 Compatibility:
As I'm writing this, Build 42 is not out, but I already know that this mod won't work as I'm using some awful hack from the dev in the lua file that handle inventory. They announced a complete rewrite to move this to the server. There no way this hack will remain in the code and I couldn't find a better way so it's unlikely I will be able to fix this. *Consider this mod deprecated once B42 is out.*

Doesn't work for me. I get an error and can't select any containers from the inventory (using Clean UI mod).

`attempted index: OnRefreshInventoryWindowContainers of non-table: null
function: FloorFirstMain.lua -- file: FloorFirstMain.lua line # 19 | MOD: 地面优先显示 Floor First
java.lang.RuntimeException: attempted index: OnRefreshInventoryWindowContainers of non-table: null
at se.krka.kahlua.vm.KahluaThread.tableget(KahluaThread.java:1667)
at se.krka.kahlua.vm.KahluaThread.luaMainloop(KahluaThread.java:479)
at se.krka.kahlua.vm.KahluaThread.call(KahluaThread.java:173)
at se.krka.kahlua.vm.KahluaThread.pcall(KahluaThread.java:1963)
at se.krka.kahlua.vm.KahluaThread.pcall(KahluaThread.java:1760)
at se.krka.kahlua.integration.LuaCaller.pcall(LuaCaller.java:76)
at se.krka.kahlua.integration.LuaCaller.protectedCall(LuaCaller.java:117)
...
`