Not sure how relevant that is as phone pouches/sleeves are not difficult to find (even customised ones), not to mention socks and/or gloves 
but there is a lady in Portugal who also does that, and I find her products pretty cute
https://www.etsy.com/pl/shop/Driworks?section_id=22553460
Finally, there is one extra store planning to deliver dedicated FP5 cases, and FP4 ones got a good review here
The store got the dimensions for FP5 totally off though