Monaco can indeed be a great option for personal residence especially from the tax perspective.
However, you might want to take a second look in regards to how to best leverage︆ your Estonian structure, and the benefits of Estonia in the context of international tax planning.︇
Even by keeping your Estonian tax residence you could easily reduce your taxes substantially by︈ restructuring your business. If you want to maintain a valid tax residence certificate what speaks︉ in favor of Estonia is the absence of need to reside in the country to︊ qualify as a tax resident.
The certificate of fiscal residence in the Principality of Monaco︋ may be obtained by any person meeting the relevant conditions and in particular by any︌ person who resides in Monaco for more than 183 days per year.
As you have︍ realized cashing out profits from your business as dividends in Estonia is far from optimal.︎ Structuring an US LLC to receive royalty payments from an Estonian resident company doesn't seem️ like a great idea either due to the 10% withholding tax. There are better jurisdictions for this which could offer overall zero tax rate, but then you're still facing the issue of transfer pricing.
However, an US LLC owned by you and structured in an unincorporated partnership with your Estonian entity could result in a close to zero overall effective tax rate.
And there are more structures that could help to optimize your tax position.
Monaco has signed up to AoEI, CRS, and it does have a corporate tax + permanent establishment regulations, which haven't been known to be enforced for offshore companies, but often︀ there is at least a theoretical risk that could materialize in the future.
Monaco has︁ a great reputation, and it seems to be somewhat submissive to EU demands to avoid︂ being grey listed, like implementing ubo register.
https://www.lemonde.fr/en/les-decod...principality,crimes, in particular tax fraud,
https://www.offshorecorptalk.com/th...orra-monaco-and-san-marino.43644/#post-286162
Regardless how︃ you move forward, do yourself a favour and seek legal advice to at least understand︄ your risks and how to mitigate them.