Having to keep your Google Shopping Ads up to date constantly with every price or availability change can be tiresome especially if you have lots of variants that are constantly changing.
Thankfully Google Merchant Center by default enable automatic item updates allowing you to not have to worry about if your Shopping Ads are up to date.
Please note, Feedoptimise handles all those updates for you already but in some cases when your prices or stock changes very frequently between feed updates then automatic stock and price updates might help to reduce interim disapproval rates.