Hello @ikendal ,
If you want to put PNGs in external flash, you can do specify it from TouchGFX designer here :

How much your SVGDatabase takes in memory? (You can check that from the map file)
Do you have a lot of SVGs in your project?
The trick to put SVGs in external flash is to write this in the linker script :
ExtFlashSection :
{
*/SVGDatabase.o(.rodata.*)
} >EXT_FLASH
you have to put these lines before the .rodata section (which goes to flash by default)
/* Constant data into "FLASH" Rom type memory */
.rodata :
{
. = ALIGN(4);
*(.rodata) /* .rodata sections (constants, strings, etc.) */
*(.rodata*) /* .rodata* sections (constants, strings, etc.) */
. = ALIGN(4);
} >FLASH
Hope it helps :)