For FEBuilderGBA, the free space in the middle of the ROM means the space of 0x00 or 0xff that is 8kbytes or more.
Custom spell patch , and wav files that are edited in a casual manner will create a vast 0x00 area, so this is not a misconception.
Therefore, if it is a small area of 8kbytes or less, that area is dangerous and will not be reused.
If free space is not found, insert it at the end of the ROM.
However, since TLP has already alloced 32MB area, the last area cannot be used.
In this case, you can use rebuild to relocate the extended area to bring the shredded area and unused data to the front.
However, rebuild is not available for TLP.
Since TLP has many unique ASM patches in the extended area, they cannot be moved.
For unknown patches, the ASM length is automatically measured.
but, this logic is not yet certain.
(If even one byte makes a mistake, everything will collapse.)
Therefore, TLP with a large number of unknown patches cannot be rebuilt.