What I find interesting is some of the bidding problems that one sees in every day play. Not the crazy 7-4 hands where slam was cold because pard was void in another suit and had the trump Jack. But the more common ones, like do you bid over the premept, and if so, how?
I'll take a dissenting view on the conventions people use here. While I enjoy reading about all these systems, for 99% of players they will have almost no impact (other than to confuse the opponents and pards).
From time to time I have asked real experts (Bobby Wolff, Mike Lawrence, Larry Cohen, Fred) about a few conventions/leads/signals. They all pretty much said the same thing "it doesn't matter much". Since I throw away points left and right on bad play, gaining 0.0078 IMPS by using the XXX convention is a waste of my time.
In reading books on defense it’s obvious that the name of the game is counting/visualization and reasoning what layouts can exist or need to exist. We are on defense about half the time, so that’s where we should concentrate our energies.
Concentrating on complex conventions, rather than (for example) working on situations that come up frequently (NT contract - pard leads the 3, dummy has the Qx and rises with the Q, do you signal Attitude or Count?) will cause you to misfocus your time.
Its fun to read about these conventions.
Its fun to try them.
It’s also unlikely to have much impact on your game (probably no impact unless you are at the expert level).
The reason Experts use lots of systems, and accept the complexity is they are fighting for every edge. They are already expert card players. For those who are no (like me!) it’s far better to spend your time reading and rereading books on defense:
Eddie Kantars Modern & Advanced Bridge Defense
Mike Lawrence’s Defense
Kelsey’s Killing Defense and More Killing Defense
Partnership Defense at Bridge - Woolsey
Test your Defense - Mollo (outdated bidding, but has a few nice hands and leads)
Opening Leads - Mike Lawrence
Older books I have but haven't read
Defend with your Life - Kantar/Reese
Defense in depth - Hoffman
There are newer books I own but haven't read yet
Demon Doubling, demon defense - Boehm
Priebe has a book on Visualization on Defense
Pottage has Defend these hands with me
I see all these people in BIL with complex conventions on their profile.
I see many BIL "graduates" that list themselves as Advanced.
Complex conventions don’t make for a good or advanced player.
Stick with the basics and forget all the complex systems, until you are very comfortable counting AND your card play is correct.

OK, rant mode off.