Zone 2 probably right.
The other way to think about it is, what are you trying to achieve, because each training should have a purpose.
So if you think of it that way, you’d rarely be ever wanting to do above z1 or z2 post workout. Like for example if you finish a bunch of hard intervals, either you went hard enough and got the stimulus you wanted, or you didn’t. If the former, why do anything harder than “easy”? You hit it hard, got sufficient benefit, just be done. Every once in a while you might want to test yourself and really empty the tank, but that’s rare and I think it’s best to approach that intentionally. And if the latter—if you didn’t bury yourself deeply enough—again why do sweetspot? Better to add another interval or go harder in your intervals.
Training a variety of durations and energy systems in the same workout, I think you can do it and probably helpful sometimes as you prepare for race season, but I wouldn’t do it regularly because load and recovery time get harder to predict and manage. And the more variables you toss in, the harder it is to identify the impact of each one.
Some people will be like “oh but TSS normalizes and you can compare apples to apples,” but I don’t think that’s true. TSS and CTL are not your fitness, they are proxies for estimating it.