The design must support the dual role of these pins. The pins need to return to the boot configuration levels whenever the boot configuration is latched. This is indicated by RESETSTATz low on most devices.
Boot configuration can rely on the internal pull-up or pull-down resistors for most devices. However, if any track, even a test pad, is added to a pin, an external resistor must be added to maintain the rated noise immunity.
Sometimes boot configuration inputs are multiplexed with other interfaces like timers, which are often overlooked. These pins must also revert to their boot-configuration level whenever it will be latched.
Internal resistors can be as low as 8K Ω. This must be considered when connecting an external resistor to oppose it. Additionally, when multiple pins are bussed together, the combined leakage current of the internal resistors must be considered.