I'm polarizing like a mofowka. On workout days I may do 3hrs, but the first hour is mid/high z1 spinning to my workout terrain, the middle 1.5 hours are smashing myself to bits, and the last hour is spinning home mid/high z1. On a vo2 day that will be 200-220ish TSS, which is definitely enough. An FTP day may be 4hrs, the first hour is mid/high z1, the middle 1.5 are smashing myself to bits, and then I take a longer route home and do high z1/low z2. When you're doing a lot of smashy stuff you tend to need to do a lot of lower key stuff if you don't want to unravel.

The days where I throw everything in tend to be the last day of a block or the day before a full off day, and I usually have a real build workout the day beforehand. So like for example, the last 2 days of my last block were 3hrs with 35min of vo2 @ 200tss, and then 5hrs of group ride hell which was a lot of ftp, tempo, z2, a little vo2 (though I was too tired to really hit that zone), and standard issue 30sec surge stuffs, for a little over 300tss. It took me like half my rest week to recover from that last twist of the knife, which is why kitchen sink smash workouts tend not to be a good idea; the amount of time it takes to legit recover from them winds up making you miss a workout or two.