MySQL binlog format change from MIXED to ROW
I've watched the move from STATEMENT -&gt; MIXED -&gt; ROW over the past decade or more.  There has been virtually no hiccups.  So, I would not worry.
ROW is essentially required for some clustering solutions, etc.  There are subtle things that can go 'wrong' in STATEMENT replication, where ROW solves it.
If RDS requires ROW, go with it.