Optimize for low memory use?

[GSI]

I'm using Miniflux v2.2.1 with ~30 feeds on an old Raspberry Pi. Typically I have some 150 MB of RAM available.

It used to run fine, but recently the OS has to kill the program regularly:

[1383230.652600] Out of memory: Killed process 16052 (miniflux.app) total-vm:554492kB, anon-rss:137368kB, file-rss:4kB, shmem-rss:0kB, UID:985 pgtables:168kB oom_score_adj:0

I suspect that these crashes may be related to having set some feeds to "fetch original content" - which I only recently learned about. I'm not sure though.

As a first mitigation attempt I set BATCH_SIZE=1, but that didn't prevent the OOM's.