A 'Packs Off' Take-Off actually puts the engine in a MORE critical bleed configuration than a 'Packs On' T/O. The engine in a Packs Off take- off has a reduced compressor stall margin due to the absence of 'bleed offload' via the packs. Various 'power by the hour' engine contracts call for periodic High-Power engine runs (usually 'ground runs') for performance retention guarantee. Generally, you can show compliance by a similarly limiting take-off configuration if you wish to avoid the maintenance costs / down-time of the high-power ground run.