Regard Portuguese lawyer, I have a great one. If someone needs - can PM me and I will gladly pass along her details. Have recommended to a few golden visa investor friends, and they have all been satisfied with her.From personal experience (a few Golden Visa investor friends), I think Portugal could also work out. Basically get in on the Golden Visa route. From what I have heard they used to be fairly flexible on the source of funds. Maybe are still...
Also, maybe by now you can somehow find Portuguese lawyers who can help you use the crypto for the 300-500k investment.
You get residency that way and then long term crypto holdings should be tax free in Portugal (again you should check this with a few local lawyers). Unless someone has direct experience here ?
As you want to get into the EU anyways you could skip 1 year (Dubai) right away and be on a 6 year path to citizenship already. Then move to any other EU country you want after you naturalise.
Of course this depends if you can convert the crypto into the Golden Visa and they accept your source of funds. But you could confirm this with some local lawyers I am sure.
Dubai setup seems great, but if Portugal works you could save some time overall.