The block is CRS on the newer ones ( and the actual vintage ones) so it's far harder to get them to stick but you should lube the thread anyway. You have to be unlucky or pretty ham fisted to break one off in the new version particularly if you make sure to use a decent quality arm. Never use one that you don't know to be from a quality manufacturer. I find the last USA Fender standard strat issue before it went to push in to be very durable and a nice fit in the thread without much slop.Apparently the Fender vintage reissue trems have the same problem of the arm seizing when tightening a bit too much
That is fine if you want the zinc block. The one with a steel block is the TS. The spring is to push back a little and give some tension in the arm and it will help against getting the bar stuck. I do think that you should easily get yours back working without the need of a back up.I also noticed it comes with the spring inserts, so that should help too, not?
They are quite a bit more expensive than the Gotoh though.
I found one on reverb: €57,5 + €11,90 shipping
The Fender is €159 at Thomann