Can/should you hack the generator to have a different socket? No, that'll void the warranty, risk damage, violate Code (NEC 110.3), and affect insurance if there's a loss.
Can you use an adapter cable? Absolutely.
Can you make an adapter cable? Sure. You just need some 10/4 cordage (not to be confused with 10/3 Romex, don't use that) and the appropriate ...
If you talking about upgrading the generator so you can get 30 Amps instead of 20 Amps, like tapping into the 8000 peak for more than a few seconds, no you can't. You'd have to replace the generator. If you're just talking about replacing the outlet to accommidate a few cords you have around, then that you can do but you'll still only get 20 Amps out of it. ...
This is largely impractical.
Your generator's 240V is 120V-neutral/ground-120V with 240V between the two hot wires, and 120V from each to neutral/ground
Your house power is 240V-Neutral/ground. One hot wire with 240V to neutral/ground.
That's not even getting into the fact that the generator is 60 Hz and the house power is 50 Hz. Which your computers and ...
That is an improper connector for a "suicide cord" - remove it and replace it with a proper "inlet." Which is a "male connector you mount on the wall."
Never heard of the place that had a usable picture of one, and no endorsement is implied. This one hapens to be "twist-lock" (L prefix) style. The pictures I could find ...
On cost, those transfer switches typically cost between $350 and $550 depending on number of switches.
A 12-space subpanel is around $40, interlock $30, 2 breakers for the interlock $10 each, plus a breaker in your main panel (normally $10, but ??? with your panel). That gives 8 "spaces" for 8-16 circuits.
So you're talking $100 for a 12-...
The big problem with Reliance 6 circuit style beside lack of flexibility is they create a rats nest in the panel.
But your bigger issue is Federal Pacific, see Wikipedia:
After the 1979 sale of Federal Pacific Electric to Reliance Electric, a unit of Exxon Corporation, Reliance reported to the U.S. Consumer Product Safety Commission that the Stab-Lok ...
No need for an interlock. There's no safety issue here.
The reason for the utility/generator interlock is to prevent back-feeding the grid and killing linemen, as you note. Solar grid-tie inverters don't need that because they comply with UL 1741 (or better!)
But that's not all UL 1741 does. It also makes grid-tie inverters play nice with generators. The ...
My guess is marketing. They position the price of the limited version to compete with some other manufacturer. If you want the full feature you have to pay for it.
Kind of like tethering computer to phone for internet. Almost all phones are capable of it, some carriers limit which plans are allowed to do it.
Who knows? Ask UL. Could be the neutral bars aren't big enough, or they had a production issue and were forced to improvise.
What is the case, however, is that model is listed for 6 spaces not 8, and so it is not UL listed for 8 spaces.
Per 110.3(B) you cannot modify the panel. I would take it back and get the 8-space.
My understanding is that you let the solar system determine what it wants to do, or you change it to work with a battery/inverter storage solution that allows grid-tie AND grid backup. At least some of those do have means to allow a generator in to assist when needed.
If the solar system considers the generator to be "grid quality," it steps in and ...