Here's an update from the previous article you shared in another discussion which was an article from Feb 2017 tested on diabetic mice. From what I have read, it's safe to take for ED but not ready for prime time for neuropathy and needs more testing with randomized controlled trials.

"Discussion and conclusion
In animal models, PDE5 inhibition appears to decrease oxidative stress and reduce some of the micro- and macrovascular complications associated with diabetes. However, data from human trials are limited and largely inconsistent, highlighting the need for adequately powered, randomised-controlled trials in diabetic cohorts in order to fully assess the benefits of PDE5i in this group of patients."
--- Nov 2022 - The efficacy of PDE5 inhibitors in diabetic patients:
https://onlinelibrary.wiley.com/doi/full/10.1111/andr.13328