Last I saw the claimed matching range of Tuner Genius was minimum 3:1. Keep in mind that just because a tuner may capable of matching a higher SWR load does not mean that it will match any load showing that SWR. It depends on the characteristics of the load: band, high (>50 ohm) or low (< 50 ohm) Z, resistive or highly reactive load, etc. Most tuner specs are based on resistive loads, so don’t mean a lot in the real world.
The MFJ 998 specs show a matching range of up to 32:1 SWR for loads over 50 ohms but only up to 4:1 SWR for loads under 50 ohms. Note the “up to”. Throw in significant reactance and those matching ranges will decrease. For example, my LDG 1000 has a claimed 10:1 matching range, but my 160M dipole has a freq. range where the LDG can’t find a match at even a 3:1 SWR.
To me the big advantage of the Flex tuner is integration with the Flex amp and radios via LAN. I don’t expect a wide matching range at high power with a switched inductor/capacitor tuner like this.
You asked for suggestions for the PG XL tuner design. Here are mine. The PG XL is a high power (2 KW) amplifier and the tuner will provide rapid switching from frequency/band through the use of high current relays to select L/C solutions. The PG XL is promised to be unlocked for MARS operation. The only exiting amplifier in this market space is the SPE Expert 2K-FA which is also a 2KW amplifier. It has an internal relay switched tuner which can be unlocked for MARS operation. That amplifier has 6 transmit coax connectors for automatic selection among 6 antennas. I would suggest that the PG XL external tuner have 8 transmit coax connectors so users will not face complex switching using additional external coax switches.
When the MARS unlock ships I will be using the PG XL for MARS regional nets and MARSRADIO. As such I monitor 4 or more MARSRADIO channels, at least one MARS regional net channel, and sometimes FT-8 channels in the ham bands on my FLEX-6700. The PG XL tuner will select among many available antennas and connect to the 2 transmit channels on my FLEX-6700. With relay tuning switching between all channels, whether ham bands or not, should be quick.
One more consideration. The cabinet should hopefully be no larger than the cabinets for the FLEX-6500/6700 so everything will fit into rack width cabinets, or smaller.
The market is larger than MARS. There is also MARSRADIO (which can use 2KW legally), DHS SHARES, FEMA and the CAP.
Thank you for considering my suggestions.