Hi, please be assured that Samsung always strives to provide the best user experience on the device, We’ll ensure you that it will be considered as feedback and value your time contacting us.
We certainly bring it to our team for further review.
Hopefully, the feature that you are expecting might be added in future update.
Moving the comma (,) to the left of the spacebar on a regular keyboard isn't something people usually do. Keyboards are made a certain way, and it's hard to change them physically without altering the keys.
But there are some special keyboard apps or software that might let you make your own keyboard layout with the comma where you want it. Just remember, this only works on certain apps or devices, and not all of them can do it.