"Resolving replication conflicts" section suggests a way that produces deprecation warning

[olegrok]

The recommended way:

local my_space_name = 'my_space'
local my_trigger = function(old, new) ... end -- your function resolving a conflict
box.ctl.on_schema_init(function()
    box.space._space:on_replace(function(old_space, new_space)
        if not old_space and new_space and new_space.name == my_space_name then
            box.on_commit(function()
                box.space[my_space_name]:before_replace(my_trigger)
            end
        end
    end)
end)

after tarantool/tarantool#11756 that way produces "space on recovery triggers are deprecated". Please update doc to provide a correct/new way to setup triggers.

[olegrok]

The answer is quite simple. You need to use trigger module. It allows to setup triggers even on non-existent spaces before box.cfg.
One-line solution instead of on_schema_init + on_replace + on_commit.