Tried to list the space as recent as last week - some of the promo space that I saw:
Seattle Amsterdam 2/24/2023 31500
Seattle Amsterdam 2/8/2023 31500
Seattle Bordeaux 2/22/2024 31500
Seattle Bremen 2/22/2024 31500
Seattle Frankfurt 2/22/2024 31500
Seattle Gothenburg 2/22/2024 31500
Seattle Hamburg 2/24/2024 31500
Seattle Rome 2/24/2024 31500
Detroit Toulouse 2/21/2024 31500
Detroit Osaka 2/17/2024 47300 only 1

Most of them gone by now - but have not researched other dates. Managed to get 2 to KIX, starting at YUL at 47.3K ea. We are visiting friends in Montreal already - so might as well keep flying eastward.

Last week, I also spotted a lot of space from East Coast (mostly JFK) to UBN at the promo level, but getting out of UBN is a pain. I think the only decent outbound from UBN is KE to ICN.

I posted abt TK own web search being so buggy. I booked ours using their app - which is super seamless compared to their web-based tool. The web search does give weekly search capability - but does not show directly business space availability. If you search, it will show 1 week block, with the lowest available displayed (irrespective of Y or J). If the promo J is the lowest on that week, you will immediately know that there is promo space available. But if on the same day, both Y and J promo are available, the Y promo is displayed so you have to click on that date to determine J availability. The other quirk is the web tool does not allow searching of more than 1 space (at least for me), even though if space for more than 1 is available, it will still show them. My recollection is that to book for more than 1, I have to call.

The app, on the other hand, once you id space availability, you can use it to book right away - and that's what I did.