Debuging Messages inside block?

I know that the screen is not refreshed until all stacked action inside the block are executed.
I just tried to call notifier several times at the different levels of my block and was surprised to see that notifier messages popped up in reverse order.
So is there still some way to produce visible debugging messages inside the block so it shows the process if sub-blocks execution?

I prefer to use a logger procedure. Here are two of them …!msg/mitappinventortest/II_RlElGddU/J0q_E-2rAwAJ