I have found 4 answers that seem promising
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Low memory, apps crashing - change zram settings or add swapfile? [4.x] - #22 by Schrdlu
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Low memory, apps crashing - change zram settings or add swapfile? [4.x] - #48 by Ride92
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Low memory, apps crashing - change zram settings or add swapfile? [4.x] - #49 by lkraav
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Low memory, apps crashing - change zram settings or add swapfile? [4.x] - #52 by lkraav
Unfortunately, you are reported that no one of them is working. I wish to point out that an Xperia 10 II refurbished would cost between €120 and €240. While a Xperia 1 II with 8GB is about €400 and Xperia 1 III with 12Gb is over €500. It is a huge difference in price.
IMHO, swap on internal SSD disk is the best way to destroy your deive storage capability with the solely result that after some time (may be one year) your smartphone is degraded to a piece of junk because when the internal SSD lacks of fail-back blocks, it is dead also and expecially in performances. This could explain your experience.
The 90-95% of zram of the available CPU RAM (the let after GPU took its part) is the only long-term solution about RAM scarcity on cheap devices. Well, not so cheap because with a less than €300, I have bought a brand new A52s with 8GB at the beginning of 2022.