The C4 has less gain than the DB8e and would make WFTV ABC 39 even more unreliable, but you are welcome to try it.
https://www.antennasdirect.com/cmss_...-sellsheet.pdf
The DB8e, with both panels aimed in the same direction, is the current champion when it comes to UHF gain.
https://www.antennasdirect.com/cmss_files/attachmentlibrary/Technical%20Data%20PDF's/DB8E-TDS.pdf
Would the 91XG be acceptable?
https://www.antennasdirect.com/cmss_files/attachmentlibrary/Technical%20Data%20PDF's/91XG-TDS.pdf
The tvfool reports for 2Edge signals are less accurate, so it is difficult to predict results with the accuracy you would like. With so many factors involved it isn't possible to make a guarantee.
You must expect some experimentation will be necessary. It might boil down to making a choice between reliable reception and appearance.
If the antenna is outside, the coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC), the mast should also be grounded in a similar manner to drain any buildup of static charge, but the system will not survive a direct strike.