Well there is 24 weeks between now and BWR. I would just stick with the plan you have laid out. Instead of the race do a segment or hill climb that is similar to test yourself. It will be beneficial to get in some intensity right now. You don’t want to go basically all year with all base. Good to train your other systems.
Plus if you do your hill climb plan now when you finish it there will still be 18 weeks till BWR. I would recommend a week of very easy riding, like a midseason break. Then start back up with sweet spot training before gravel grinder plan into BWR. You will want to build your CTL back up to where you had it at your summer peak. That shouldn’t be too hard to do. When we get close I can put in a midseason break week and plug in the part of the sweet spot plan you should start with.
Looking at your Performance Manager Chart your CTL will still go up over the next several weeks! So by doing the climbing interval plan you are not going to be losing any fitness. It still has an upward trend.
You had a great simulation ride! Wow a 118 mile, 12,000ft of climbing and 9 hours! It would be great to repeat that type of effort over the summer. These are the type of rides that will really help you prepare. Then you should have another one about 3 - 4 weeks out. But we can plan those in your plan as we get close. Seems you didn’t start off too hard which is good! Sometimes you roll out too hard with lots of tempo and sweet spot and really crack at the end. Yes power was lower at the end but you were still able to finish the ride. You don’t really know these things until you complete these type of rides. Your first 4.5 hours was mostly uphill and you did .63 intensity factor while in the last 4.5 hours you did .52 so you know how much even just easy zone 2 riding can take out of you.
One thing I would recommend is maybe pushing the pace a bit more on your weekend sweet s pot rides. So looking at the ride on May 9th it was a 4.5 hour ride yet you spent nearly 2 hours of it in zone 1. Try to get a bit more zone 3/4 time in the ride, 83 - 97% of your FTP. This would really help your aerobic engine on long races / rides. Start pushing the pace with the 3 hour rides were you know you can get through. Then work up to pushing hard for the 4 hour and 5 hour ones. For the most part you are hitting TSS marks so that is good! But try getting them in the planned duration. So you instead of doing around 50 TSS per hour try getting up to 60 TSS per hour on these Sweet spot group rides.
Not sure if you made notes about what you ate, drank, when, how much, pacing and etc but that is important so you remember. This way you can make changes, tweak or repeat if it worked. Putting them in TrainingPeaks is usually a good spot.