Somewhere in the forum I posted my upgrade for vigor d9. I made it 44/24t double with 12-34t 10 speed cassette, so I get 14.0-72.6 gear inches. I would have preferred at least 76 gear inches because I run out of gears sometimes when going on a slight downhill, but it lasts for less than a minute at a time so the loss in time savings is only a few seconds.
i custom assemble the cogs to 12,13,14,15,17,19,21,24,28,34. So I get very close spacing at the top and wide spacing at the bottom range.

The 20t jump of the double is fine as long as I had set it up well. It needs a chain catcher. The 8,9,10 gear on the small chainring will rub the chain on the outer chainring so I don't use those gears, and don't need them because they overlap in range.

I also use a SRAM yaw FD so I don't need trim. I previously had a Shimano 4700 FD before it collapsed, but I had to bend the inner cage to widen it because of the extreme angle of the FD due to the thick seat tube. It also had very specific trim settings. With the SRAM yaw FD I only had to add some spacers under the cage screw and bend the front of the cage until the tail formed the same gap width as the washers. I could also use the 4700 trigger with trim but I simply adjusted the cable slack and limit screws so that trim index didn't do anything. You can find more information here

https://www.bikeforums.net/folding-bikes/1185561-how-bend-front-derailleur-fit-folding-bike-frames-thick-seat-tubes.html