IBKR does not like you sending money to them, converting it (cheaply) and then sending it on.
For smaller stuff they lose their advantage anyway. And it sounds like you would use it for smaller stuff.
Wise is pretty good for like 1k-10k (not bad for above but obviously at some point IBKR becomes cheaper). Anything below I just use my Revolut card. For vacations I prep by using up the free exchange per calendar month in the months before the vacation already.