Linux: Swap out in bigger chunks

Not. It isn't possible.

Linux Kernel decide through different algorithms about RAM, Swap Spaces, Last Swap Location Used, Disk Cache Responsive, Swapiness and so other things when and how to use Swap memory allocation.

The system can't just wait to have "10MB> page collection" because memory managing is on-demand to avoid system freezes and process killing.

However, some bugs related to RAM and Swapping management have been reported during the years due to really bad performance when the system starts to swap.

I can say you that Disk Usage is improvable using zswap, because the biggest problem here is the exponential multiplication of pages when arriving swap (that's because memory pages linking).

zswap compress that multiplication, making less disk reads/writes and can have a prominent impact on your CPU usage.

zswap is kernel-managed and you have a lot of useful low-level configurations to adapt it to your system needs.

https://www.maketecheasier.com/use-zswap-improve-old-linux-performance/