Discussion at MJF-986 ATU – flashover analysis and MJF-986 ATU – flashover analysis – comparison with 500pF T match was focused on the voltages that develop inside the ATU and internal loss at well below the advertised 3kW power rating of the MJF-986 ATU.
A relevant question is, is the antenna + feed line the underlying problem?
Avoiding flashover in baluns and ATUs discussed the subject of flashover in terms of the ATU antenna terminal voltages showing a pink zone on the Smith chart that results in high ATU voltages and suggests adjusting feed line length for a given radiator to avoid operating the the pink zone. Adjusting the radiator length is another option, essential the combination of dipole length and feed line length contribute to operation in the pink zone. Read the article to find how to identify the pink zone for your own voltage limits and power. Note that multi band optimisation, finding a solution that works on all bands, is more complicated.
Whilst a random length dipole fed with a random length of random two wire line might have appeal, it might be superficially simple and have random results!
That said, the Differential T ATU sacrifices performance for convenience, and may develop higher internal voltages and loss than an ordinary T match with large capacitors.
Antenna SYSTEMS should be treated as a system, and designed at that level rather that a hotch-potch of components that are not well integrated.