Roamify does provide unlimited data eSIMs for the Isle of Man. The plans are available for 1, 3, 5, 7, 10, 15, 20, and 30 days with prices ranging from $5.00 to $72.00 USD. All unlimited plans include tethering and are transmitted over 5G; the data allowance is described as unlimited, but the provider notes that speeds may be throttled after heavy use.
If you need details about speed limits or want to confirm the Fair Usage Policy for a specific plan, you should contact Roamify directly to verify how the data is managed and what typical data caps at normal speed are.