Canadian student banned from US — can I apply to London/Asia discovery days at quant firms, or are they region-locked?

I’m a CS student at a Canadian university with a strong competitive math background (olympiad-level, USAMO qual, AIME top 2.5%). I’d be competitive for quant firms in the US, but I’m currently banned from entering due to a previous overstay.

So I’ve been looking at discovery day programs at firms’ international offices as a way to get my foot in the door. But many of these seem restricted to local students — for example, Citadel’s London discovery day says it’s for “European students.”

My questions:

∙	Has anyone from a Canadian university successfully applied to a London or Asia-based discovery day at a quant firm?

∙	Are these “European students” requirements hard filters, or is there flexibility if your profile is strong enough?

∙	Which firms (Jane Street, Optiver, IMC, Citadel, etc.) are more open to non-local applicants for their discovery programs?

∙	Would firms think it’s weird for a Canadian to fly out for one of these?

∙	Or am I overthinking this and should just apply anyway?

Don’t want to waste my time if these are strict regional filters, but also don’t want to miss opportunities just because I assumed I couldn’t apply.