Keep On Roaming does not offer a true unlimited‑data eSIM for Austria.
The plans marketed as “Unlimited” actually provide only 1 GB per day (or 1 GB for a single day) and have a fixed validity period, so the data allowance is a hard cap and the speed is not unlimited once the cap is reached.
If a larger data budget is needed, the provider supplies fixed‑data plans that can be used for the entire validity period. For example, Austria 100 GB for 30 days costs $53 USD, Austria 50 GB for 30 days is $27 USD, and Austria 20 GB for 30 days is $14.46 USD.
These plans give the specified amount of data that can be used until the data is exhausted; there is no further speed throttling after the data runs out, but the data is not unlimited.