see https://github.com/paly2/MoreMesecons/commit/b6cb4bc246509cfc150cb4166a0fb78af8170627

mesecons_overriding.lua

local current_pos

local actual_node_get = minetest.get_node_or_nil
local function temp_node_get(pos, ...)
	current_pos = pos
	return actual_node_get(pos, ...)
end

local actual_turnon = mesecon.turnon
function mesecon.turnon(...)
	minetest.get_node_or_nil = temp_node_get
	--local v = actual_turnon(pos, ...)  commented because mesecon.turnon now doesn't return sth
	actual_turnon(...)
	minetest.get_node_or_nil = actual_node_get
	current_pos = nil
	--return v
end

local actual_is_conductor_off = mesecon.is_conductor_off
function mesecon.is_conductor_off(...)
	if current_pos
	and is_jammed(current_pos) then
		return
	end
	return actual_is_conductor_off(...)
end

local actual_is_effector = mesecon.is_effector
function mesecon.is_effector(...)
	if current_pos
	and is_jammed(current_pos) then
		return
	end
	return actual_is_effector(...)
end