You could get yourself a Greenland paddle and forget about feathering.
But I repeat myself. Sorry.
Have you tried one?
Are you asking because of pain?
Wrist, elbow, shoulder?
If you're happy and nothing hurts, there's no need to change, though it can be useful to experiment.
I started with zero feather, years later went to a very mild (15 degree) feather for a year, and at the beginning of the following year made my choice based on which way felt more natural after taking the winter off. Back to zero feather it was. I was able to quickly adapt when I switched both to and from the 15 degrees, which is not a drastic amount. Also, I got my "other side" roll while using feathered; when I switched back to zero feather I still had it. Don't make it more complicated than it is: what feels best?
P.S.--During the year I paddled using 15 degree of feather, I tried going to 30 degrees and hated it. YMMV.
Started with 90. 75 is better
I think zero might be too little. Some feather tends to break inefficient gripping and help with long use.
I believe one of the best ww paddle makers (Jimstx) favors about 30 degrees, but don’t quote me.
Have you tried a Greenland paddle?
You might be surprised. I was hooked in 10 minutes.
Make a choice and stick to it
The lady who was my instructor for an introductory class on kayaking showed both techniques and told us to try both and make a choice. Once that choice was made we should stick with it forever more. Her reason for telling us not to switch or change is that some day, some time when we least expect it, we are going to get in a situation where we must act quickly and without thinking. For example , BRACE NOW! If you always use the same technique, you will adapt and everything is automatic. I think that is good advice for you. Stick with whatever technique you have been using unless it is causing you harm.
people are different, that’s why
30 degrees works for me and my stroke and physiology, that's why.
Do me a favor and play with stroke angle. Then you'll discover that stroke angle influences wrist cocking. Add physiology or build, and you have another factor.
Which is why it's nice to have options. What's your problem with someone having options?
If there were one feather option best for everyone, we wouldn't have completely adjustable feather.
Maybe for newbies
There ARE experienced paddlers who use feathered Euro or wing paddles as well as GP, and they switch back and forth.
When starting out, I agree: Pick one and stick with it for a while instead of going back and forth.