Global regularity for minimal sets near a $\text{T}$ set and counterexamples

We discuss the global regularity for 2 dimensional minimal sets that are near a $\text{T}$ set, that is, whether every global minimal set in ${\mathbb{R}}^n$ that looks like a $\text{T}$ set at infinity is a $\text{T}$ set or not. The main point is to use the topological properties of a minimal set at large scale to control its topology at smaller scales. This is the idea to prove that all 1-dimensional Almgren-minimal sets in ${\mathbb{R}}^n$, and all 2-dimensional Mumford-Shah minimal sets in ${\mathbb{R}}^3$ are cones. In this article we discuss two types of 2-dimensional minimal sets: Almgren-minimal set in ${\mathbb{R}}^3$ whose blow-in limit is a $\text{T}$ set; topological minimal sets in ${\mathbb{R}}^4$ whose blow-in limit is a $\text{T}$ set. For the first one we eliminate an existing potential counterexample that was proposed by several people, and show that a real counterexample should have a more complicated topological structure; for the second we construct a potential example using a Klein bottle.