Expanding SD card

[breakbob]

I installed my 64gb Recalbox image on 128gb SD card.
Trying to expand SHARE partition under GPart isn't possible because it's an ExFat partition and GPart not reading it. Left with unallocated 64gb space which I formatted as Ex4 under Gpart but I can't merge into ExFat SHARE partition. Same happens under Windows - Partition Tool see extra 64gb but it's not possible to merge into this SHARE ExFat partition because it's 98% or 63gb full. Do I need to format SD card in MSDOS , create .iso file and burn 64GB image onto it again? Or just format SHARE partition on 128gb as DOS, copy all folders from spare 64gb SD card onto it? Gonna take lot of time
Did anyone successfully expanded RECALBOX SD card please?

[breakbob]

PS. I also don't want use external USB for storing my Roms, I will be using 4 usb ports for controllers,mouse and keyboard