I know what I will suggest is not much of a help, but generally the big sub's is better to be placed on top of each memory page. If you cannot find how long a sub may take, then compile it in a new program file, after compilation check the length and move the sub to a better position at the final program.

Then the rest of the page can be filled with a smaller sub.

If anyone has a better suggestion, please, one step forward.

Ioannis