Data consumption when idle on metered connection

Setting up a link to a remote place with only cellular connectivity.
I am paying for data usage so I am naturally interested in keeping usage low.

How much data per month does a mostly idle Tailscale link consume?
Do I have any tools to reduce data usage?

Tailscale uploads and downloads 64.4-byte packets every 5-10 seconds. I tested it for 1 week and observed a data consumption of about 30 mb entirely from the tailscale. This corresponds to about 120 MB of data usage per month even when the tailscale is completely idle. Especially for multiple iot devices this data usage can be painful. I am following this issue closely, can someone please help us?

Warning! Excessive data usage - #33 by Pinter

I just suffered an issue of gigabytes per day of usage on my iOS device, and I’m not doing anything exotic, not using an end node or anything like that.