Changing the stripe_cache_size will not risk causing corruption.
If you set it too low the reshape will stop progressing. You can then set it to a larger value and let it continue.
If you set it too high you risk tying up all of your system memory in the cache. In this case you system might enter a swap-storm and it might be rather hard to set it back to a lower value.
The amount of memory used per cache entry is about 4K times the number of device in the array.