It was Jatill that coded/changed the shandalar button to switcher and was released in Manalink Update Dec 25 : Merry Christmas Update.
viewtopic.php?f=85&t=2002&p=26001&hilit=switcher#p26001Jatill wrote:
1) Switcher.exe is gone. Instead, there are now 2 separate versions that you can run directly (Magic.exe and MagicLimited.exe). Use one for constructed play and one for limited. If you want, you can also switch between the versions in-game through the ‘Switcher’ button. (Thanks to Snacko for answering lots of questions about dll’s, and Mathusalem for updating the art)
The main display page was done by Jatill,too:
viewtopic.php?f=85&t=1811#p23204If it is of any help in the post Differences between original Manalink and the actual one in development Gargaroz and Jatill are naming some things they changed and Jatill has listed his patch.text a scratchpad for various addresses that he needed to look up frequently.
viewtopic.php?f=56&t=5927At the end of his patch.text he mentions:
switcher: 440f33 -> 120487e
Magic Limited.exe string: 1204904
Switcher was how he renamed the button of World = (shandalar) so it seems relevant.