Some other markets may be a possibility such as Australia and Poland, I think this last one was in the likely pipeline for this year so we might get access to it before the end of the year if things have been progressing as the team expected/hoped at the start of the year.
For me, foreign markets besides their financial instruments (stocks, ETFs, bonds, etc) must have 2 very important variables, strong local currency (including free capital movements) and political stability. Besides the usual variable that is common to all markets, liquidity.
Japan, for me, is a mix of thoughts, although it’s a political stable country and the JPY (and JGB) is considered a safe-haven asset in times of risk off, the JPY and denominated instruments suffer from currency devaluations. Japan since the 90’s bubble burst is living in a low growth economy and low inflation environment, it took almost 30 years to recoup the losses of the 90s bubble burst. Some natural disasters and nuclear risk.
Hong Kong is being eaten by China, with the political, social and economical consequences.
Other Asian countries, the Southeast Asia (e.g. ASEAN countries) are prone to natural disasters, political and social unrest, their currencies are sensible to hot money and currency attacks
In Europe, I see other more relevant markets, besides Poland. For example, the Nordics countries (more politically and economical stable), or Italy (3rd largest EU economy).