We have always followed the reply from Meepledrone that was posted in the comment section for the tower expansion:

Example 1

Example 2

Meepledrone's response was

Example 2 is correct.

You take into consideration tiles and empty square spaces when calculating the tower (square tiles being considered in this case only). "This reach goes beyond empty spaces on the board" is explaining the case of the tile numbered as 2 at the bottom. The bottom stretch from the tower has a empty space at distance 1 and a tile at distance 2. The empty space will not prevent you from capturing a meeple place on tile at distance 2 "beyond an empty space".

Note there may be several empty square spaces and each one will be considered when calculating the tower range.

and those are the rules that we follow for any movement over empty spaces.

Our group of four has discussed a house rule for this situation, if you land on an empty square, your meeple falls out of the game, and you don't get it back! But that is NOT what meepledrone was saying in his response for the tower.