It won't help you too much by only inrease compacF's freq. The maximum freq in cgminer for compacF can be 800 MHz. But, there are drawback in doing so:
1. the numbers of hashed local block header data won't be increased significantly by incresed freq. We want more block header data to be hashed in per seconds. There is some bottleneck to limit effect of freq increase.
2. heat will be increased significantly, which may cause burning of chip.
3. (5:14) or (14:14) or (28:14) indicator as I post before, will more significantly affect the number of hashed block header data than freq does. So, keeping (5:14)  status is better than increasing freq. 
4. Increasing freq won't increase output of found nonces, and won't increase quality nonces (which has higher diff), this is the key to success in mining. We want the nonce which can reach the target or higher diff.  Now, too many nonces with below 10k difficulty.
5. Higher freq will produce more failed nonces which can not pass 1st test under asic boost mode. ASIC boost mode in BM1397 chip may limit the quality of nonces.  I turn off asic boost, and got more quality nonce or more higher diff nonces.

6. There are more aspects which will affect the quality of mining BTC.