Carcul - welcome back. You have been missed. I'd be a little more expansive in my list of changes since your last post, though I'd say the most exciting was Steve's hidden pair elimination in the Easter Monster that Ruud refered to.
Denis Berthier has expanded
Arcilla's set approach to fish by introducing
RN and CN space - hidden XYT-chains. More importantly his concept of
nrc(t)-chains is a simple, but powerful, method to expand nice loops to include multi-valued cells or multi-location units whilst maintaining basically a chain structure.
Myth has developed
Almost Hidden Sets which is a useful compliment to the ALS in nice loops.
Champagne has developed
Full Tagging which is similar to Myth's
Molecular method.
Steve K has emphasized the use of
Matrix Representations for evaluating multi-implication networks.
Ruud has developed
Deadly intertwined Patterns which is similar to your
Two Incompatible Unique Rectangles.
Note a couple of the links won't work until the Discussions Forum is back online