If Jill gave Bob $50K over a couple of years and someone investigated and she said “Bob invests my money and does really well, is an awesome guy to work with, and helps me out from time to time on other issues. I decided to send him a gift”, I just don’t see how that could cause any problems.
Now if there was a string of texts and messages where Bob was showing Jill what a fiduciary would have made and talked about percentages and earnings in relation to his services, that might be an issue.
But if Bob never names a number and never requests anything and Jill gives him a gift, I don’t see the issue. But it does seem like a very slippery slope that has the potential for some major issues.