BOI Mortgage Loan offer - how to rate, what to seek - how to ask etc

30 years, APR 3.8% variable at 3.75% on a 90% mortgage.

I don't see anything unusual in this offer letter - then again, I'm not entirely sure what I should keep an eye for ...

I do however note no provision for extra payments (assuming at some future unlikely date we want to pay off some extra principal) ...

Be obliged for comments ... ...

I also have just received a loan offer from BOI variable rate.
What section do they refer to no extra repayments?

Usually it's the de facto case that you can make additional payments against a variable rate loan, either a personal term loan or a mortgage. You generally can't with a fixed rate loan.