Recent end-stopping experiments in TMX-Upgrade show strong plugging of the central cell by lower-density plugs, requiring both electron-cyclotron heating (ECRH) and 47^o neutral-beam injection, consistent with the thermal barrier concept. These experiments have low density (n≤ 10¹² cm^-3) due to inefficient ECRH power coupling. Hot ion and hot electron buildup are consistent with Fokker-Planck calculations. No ion cyclotron activity is observed in the plugs; occasional electron cyclotron activity is observed. With plugging, axial lifetimes (T∥ ≥ 40ms) are larger than radial ( T_⊥ = 5-10 ms) due to observed non-ambipolar ion transport. Recent tandem mirror theoretical activities are also surveyed.