I was implimenting a SP list including 50+ fields which each section should fill out by different role/department in the company. I have a look to see if PowerApp can help on customizing SP list on O365. I found this article by @Audrie-MSFT :
It will work for scenario that only involve text fields only. But in real business, we have combobox, lookup, choice, and more field types. The limitation is that if you start from scratch in tablet mode by PowerApp studio, you are not able to add those field types with above approch to the Canvas in the screen.
So to overcome the limitation, I add 4 screen (one screen per each tab) and use button click to navigate between screens and use EditForm on each form to allow user Add new/Edit capability for each element in the SP list but in seperate tab. So this way it support all fields types. The only limitation in this approach is that you are not able to create a new item, if there is a mandatory field in another tab.
I was going to add this sucessfull workaround as a comment to above blog post but unfortunatly the comment section was closed. Could you please add it or update above post as that is a popular business scenario for forms with many fields and might be beneficial for many other user.(it took 2-3 days for me to reach from your article to impliment this solution. so hopefully save others time). I can provide step by step guides, if required. Also if you could please support tabular form capability on PowerApp. Thanks