If your permafree requires a BB to work, the strategy needs a rethink.
My strategy works well for me and needs no rethinking. I made more money after I went wide with a permafree series starter even before I had a free Bookbub for the series starter.
Here's a deeper breakdown of my results, including while in KU, after I went wide but before the Bookbub, and after the Bookbub.
As you can see from my 2018 sales, each month saw a further drop in revenues for the series. If I had stayed in KU, I would not likely have gotten a Bookbub for the series starter. I tried to get a Bookbub for the series opener when it was in KU but was turned down.
When I went wide and applied for a free Bookbub promo, they approved the application.
You can see that even before I had the BookBub, which was mid-February 2019, I was making more money wide than I had in the months prior to going wide.
In Jan and Feb before my Bookbub I earned as much on the three books as I had earned in 6 months in KU.
As far as strategies go, since I was lucky enough to get Bookbub promos in the past, I took the risk of going wide.
With a permafree series starter, I did better right out of the gate even before the Bookbub.
With the Bookbub, my series made me close to an extra $25K compared to how I did in KU and likely would have done in KU if I stayed.
For those who can get a BookBub, this strategy works really well. My advice is to try everything but have a strategy in place in case it doesn't work out. Try to get Bookbubs even in KU. If you can get a Bookbub while in KU, then you might be able to get one more easily if you go wide and might make more money with a permafree series starter wide.
But in the end, we're all different, our books are different and our risk aversion is different. I decided back after KU 2.0 came out to go wide with permafree series starters and it made the difference a number of times.
Some people do really well in KU and get great results from KCD deals and Prime reading. I do better wide because I am able to get frequent Bookbubs.
If I had never tried for a Bookbub, and if I had never tried to go wide, I may never have succeeded in this strategy.
YMMV.