Well yes that many trains are going to cause gridlock – But not the kind you’re suggesting where a pass loop is completely clogged up to the point where the trains cannot get out of the jam without manual interference (I.E. trains parked at the single track parts of the pass loop) Trains would be halted at pass loops further away, or even their train stations.
These pass loops are not for major networks with multiple lines, they allow two way passing on smaller networks without having to double track the entire length of the rail. You’re going to need two tracks with pass loops of their own or more at that point. Just like in real life.
Could we please keep the discussion in one place though? It feels silly responding to you in two places for the same thing. 🙂