In Europe (with your UK eSIM):
You can roam for up to 15 days per trip with a maximum of 20GB of data per month (depending on your plan). Your 15-day allowance resets each time you return to the UK.
Outside Europe (with your Global Roaming eSIM):
There’s no fixed trip limit - you can use it for as long as you like in supported countries. The Global Roaming eSIM gives you unlimited data, with 5G speeds up to your allowance and then 4G speeds after (refer to your plan for your actual data allowances).