We already have an extensive suite of static analysis tools we use, which causes a fair bit of redundancy as we get duplicate warnings. PVS is also prone to give false warnings which creates a lot of work to identify and disable.
When a buffer update callback is called, textlock is active so buffer text cannot be changed, but cursor can still be moved. This can cause problems when the buffer update is in the middle of an operator, like the one mentioned in #16729. The solution is to save cursor position and restore it afterwards, like how cursor is saved and restored when evaluating an <expr> mapping.