In the context of geopolitics and history, there really wouldn't be a pretext for making an analogy between Alaska deciding to secede from the US or how it might be comparable to Chinese claims that Taiwan is a breakaway province?
First and foremost, we purchased Alaska from the Russians at kind of then-bargain basement deals in 1867 between then-Secretary of State William Sewell and the Russian ambassador partly due to Russia's wish that their Alaskan colony didnt Falcons into British/Canadian hands. You may not be aware of this, but if the Russians hadn't sold us Alaska, their is a very good chance Alaska eventually becomes part of Canada because up until WWI, although Canada was its own sovereign, independent nation, Britain still controlled their foreign policy and from the 1830's till signing of the Entente Cordialle in 1907, Czarist Russia and UK were involved in a near-century long military, diplomatic chessmatch historians have called, "The Great Game". " The Great Game" was sort of the 19th century's Cold War and it involved territorial disputes from Balkans, Crimean War, Baku, Afghanistan, British control over India, British expedition to Tibet in 1903, dividing Persia(Iran) into spheres of influence, how British/French and Russians were arguing about how they were going to divide up the dwindling, unreformable, centuries-old Ottoman Empire, "sick man of Europe". Russia, amazingly during the Civil War, was a staunch Union ally, while the British held deep pro-Confederate sympathies, Lord Russell even argued before the House of Commons in 1864 for British military intervention to prevent a potential race war. Russia had also discovered immense oil, natural gas resources in Siberia in the early 1860's so it made Alaskan ownership a bit of a moot point by then.
Also, most Taiwanese, if they were polled or asked, likely wouldn't want to revert back to some one-party authoritian Communist regime opposed to a parliamentary democracy, they shouldn't be forced to accept or tolerate a compromise solution which makes that a distant possibility, its not fair to them. A Hong Kong-type solution wouldn't work either because Chinese Communist leadership has actually broken or bended the terms of the handover deal brokered between UK And China back in 1984 where Hong Kong would enjoy its long-cherished democratic institutions for 50 years after their handover, "two systems, one government " agreement. Based on how riot police handled and beat up pro-democracy demonstrators in Hong Kong 3 years ago amid accusations of press/media crackdowns, limiting civil liberties, individual rights of city citizens, arresting dissidents, honestly how can any reasonable, realistic Taiwanese politician, citizen take any claims of Chinese respecting their rights as face value? Theyll gradually bend then break the rules, albeit over a decade or two, of most or any agreements they make.