My opinion would be to stick the sharable link only because of the sharable being as good as the membership link without worrying about of the additional effort.
I've got an Ancestry account and with the sharable and membership link you use both takes me to the Canadian (.ca) Ancestry server and I use the American (.com) one.
I can log in to the Canadian server without any problems, but it's actually a separate login for 2 membership servers.
Don't get me wrong... I'm not complaining nor am having an issue personally. :-)
I hope I had explained my feedback okay via text.
Besides the above, you really did a very good job with the profile. :-D