There are no limitations on the length of IR (Impulse Response) data that can be loaded into WAZA Tube Amp Expander. For example, both 200 ms and 500 ms IR files are supported.
See also the related Q&A "WAZA-TAE: IR data types (formats) that can be used".
Please use WAZA Tube Amp Expander Editor to load IR data.
Note: WAZA Tube Amp Expander Loader has been integrated into WAZA Tube Amp Expander Editor (Ver. 3.0.0 or later). Be sure to update the WAZA Tube Amp Expander System Program and USB Driver to the latest versions before use.
Download: https://www.boss.info/global/support/by_product/waza_tube_amp_expander/updates_drivers/
For detailed instructions on how to operate the editor, please refer to “Using the WAZA Tube Amp Expander Editor”.