Will my FTP increase from racing

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I have one other maybe silly question. But nobody I know personally has the answer.
So I like to do intervals twice a week combined with technique training.
So instead of doing my intervals on flat road I do them on singletrack with a lot corners, small jumps climbs and all. Some days i do shorter intervals from 3 to 6 minutes other days I go for longer ones from maybe 12 to 20 minutes.
My question is when I do these longer intervals at singletrack will I still get some of the endurance benefits I’d get from doing them at a straight road steady pace? Or is it only adding to my explosive power since it’s mostly zone6 you hit on those intervals.
Here is an example of one of my longer intervals

Now thinking about it this is basically the same question as will racing improve my ftp. It’s mostly zone 6 work but will it benefit my endurance.