Back in the days when I used to use cheques and got the odd one from the US, Barclays was the place to go.
They used to have no fee for cheques under a certain amount (think for US it was $50, and would be the equivalent for CA). Most other banks charged.
You didn’t have to bank there either, just pop over to the foreign exchange desk of Barclays.
Last time I did it was many years back though so may have all changed.
I’m guessing though the tax refund is going to be a lot more. Still I think the fee was favourable.
Alternatively you could set up an account in that currency and pay it into that, but not much use unless you’re going to spend in that currency. I do that with PayPal to receive US payments as sometimes I’ll buy from US so I just don’t bother exchanging it, but that’s electronic stuff not cheques (have to set PayPal up to accept in local currency by the way, else it converts at a hideous rate).