Comparing MasmBasic's
Insert and
Delete against the respective
FB macros written by fxm:
elementInsert(array, index, element) and
elementDelete(array, index) are only marginally slower than
Insert array(), index [, elements]

Loading array: 4599 elements loaded in loaded in 393 microseconds
inserting and deleting took 952 milliseconds
Loading array: 4599 elements loaded in 3 milliseconds
inserting and deleting took 1297 milliseconds
Attached are sources and executables. The file inc\glib.bi is required, so extract the executables to the folder where fbc.exe sits.
Note that the Gcc version produces entirely different results - something is wrong there...