The two ROM versions are the most commonly used. However, GSI has more to offer: six ROM variants, depending on the system architecture. See also “Why should I use GSI for A/B devices to some A-only devices?”.
The GSI idea was well-intentioned, but in practice various shortcomings become apparent. Bootloops are constant companions during installation. That is why it is important to know what you are doing when you want to install GSI ROMs.
The SM-A320FL is curious. The ROM e-pie-20200416-UNOFFICIAL-treble_arm64_aeN.img is the so-called A-only variant and worked on my treblezied A3 2017. On the other hand, I had to install the A/B variant of the eOS-Q-20201225 because the A-only variant ended in a bootloop. (???!)
Something else: Besides GSI ROM, have you tried the device-specific build ROM e-0.14-q-20201220-UNOFFICIAL-a3y17lte from @itsclarence?