Hi, just to add my thoughts.
Be aware of various grades of Loctite that are available from low to high strength, there is bewildering range out there. As others have said, would suggest 243 at medium strength is as far you need to go for such small treads. Grade 221 & 222 are also suitable for small treads & are classed as low strength, dismantling can be achieved my hand tools. The use of high strength grades such as 271 could result in damaged screw heads if dismantling was needed on such small screws.
Then of course be aware of the name thing. The name Loctite is to thread locking as Hoover is to vacuum cleaners. There are lots of other manufacturers of thread locking products, but to what grade? Halfords sell a product called "stud-lock", can't recall the maker, but it may be a high strength one & not suitable.
Others might have first hand experience of the high strength grades of loctite & the alternative makes.