Been reading about the Russian Revolution of 1905. It looks like there was a brief period where there was a legislative body, before being quickly undermined by Nicholas II. What if Nicholas (or whoever the ALT leader should be to make this work) did not give himself the title of "supreme autocrat" and all that implies?
The 1905 reforms were doomed almost regardless of how Nicholas felt about them, and in some sources I have come across it suggests that he did try and support the institution. The problem was that no one really expected, wanted, or worked towards the body actually functioning. The state Duma was plagued by infighting, factionalism, and personal interests from the get go and as a result very little could be accomplished without the direct intervention of the Tsar, which was just autocracy with extra steps and alot more yelling.
So even if Nicholas kept the legislature around it would have been little more than a very load detour for the emperors edicts to pass through before they became law and would be unlikely to achieve its goals. The problem Russia faced in the period is that it was going to collapse one way or another eventually. The German line about merely kicking the door in for the whole rotten edifice to come crashing down applies very well to imperial Russia. Key issues facing the country were.
1) A bad leader, I dont think Nicolas was bad deliberately, but with his father dying when he was still young he assumed power before his training to rule was truly complete, and how and why his father died (see other causes of the empires collapse) would feed into several bad decisions he made during his reign. He was not particularly fond of his rule, and that may have fed into his decisions as well.
2) Industrialization, pretty much the entire world struggled with the industrial revolution, large immigrations to cities leading to urbanization caused problems everywhere. But due to the empire's size coupled with other problems the class struggles and effects of the collapse of typical social norms would hit the empire hard. The way in which the empire modernized, with heavy foreign and state level investment and little native interest for most of the period also led to further levels of issues as the people at the top had even more reason to dislike industrialization as they were not profiting from it, while the working class still perceived them as greedy ineffectual pigs.
3) Inefficiencies, while the imperial government was not truly a feudal state like some pop culture histories say the empire's governing organs were hardly modern despite efforts at reform. Nobility still held large amounts of power in theory, but in practice they were out of touch and increasingly irrelevant as their fortunes dried up and they became more and more out of touch. What was left was often unqualified themselves.
4) Diversity, the population of the empire was probably the most racially, linguistically, and ethnically diverse empire in the world after the British. And this led to further problems as several strategically vital areas of the empire had major tensions because of these issues. Which resulted in the Russian empire trying to suppress them through violent means, which just caused further issues and more unrest.
These really just touch the surface, but should go a long way to explain that Duma or no Duma the Russian empire was not in a good place as it both needed massive reforms, but was unable, unwilling, and unqualified to enact such reforms.