Are social crises good for the bourgeoisie, according to Marx?

While Conifold is basically correct, Marx did generalize to a certain extent about crises. The dominant class will enter a crisis when the current norms, laws, and ideologies that sustain it place unbearable constraints on technical advances in the mode of production.

This is most evident in the Capitalist phase and the bourgeois revolutions, but is presumably a dialectical conundrum in any age. The laws that sustain the given order and class domination will come to seem more and more "irrational" and intolerable as the improved forces of production advance beyond them. The internal contradictions accumulate to the point of implosion.

This is not, I should add, the sort of technical determinism or "science of history" favored by Engels and, more crudely, the orthodox Bolsheviks. It would take the form, in any given historical moment, of highly complex, unpredictable stresses in the social order, involving conscious reactions, politics, and culture every bit as much as new machines and material overproduction.

Crises like the pandemic or protests simply do not rise to this level, though they could catalyze other forces, who knows? A better example of what Marx suggests would be the stresses on "national" legal-political structures and institutions caused by the computerization and globalization of Capital. Capital can extend the division of labor across national borders, yet still relies on a fiat currency secured by national debt and taxation.

Another would be the inherent contradiction between the advances of commodified digital information and the outmoded laws of ownership, patents, copyright, etc. based on 18th century bourgeois rights to "property," in the form of land or natural resources. Napster, probably more than BLM or Covid-19, presented a true dialectical crisis for the bourgeois that is still playing out. Merely human crises are just market opportunities.

The only social crisis that is unqualifiedly good for the bourgeoisie on Marx's theory of history is that one that brings it to power. The only social crisis that is unqualfiedly bad for it is the proletarian revolution that destroys its power.

Inbetween, there are only contingencies. It may happen that a social crisis involves state restrictions which, despite the bourgeoisie's general control of the state, interferes with its power to exploit and appropriate surplus value from the proletariat. A war might do this through controls on production of particular goods and services. On the other hand, a social crisis may open new opportunities - as, for instance, the environmental crisis (a kind of social crisis) which calls for new technologies and new opportunities of profit for the bourgeoisie by the redeployment of the forces of production. There can be no useful generalisations about the tendency of social crisis to benefit rather than harm the bourgeoisie - except perhaps this one.

I am not writing from a Marxist perspective, simply trying to work out how an orthodox Marxist would respond to your question.

I can offer only another book, sorry. The book is “Failure of a Revolution: Germany 1918-19 by Sebastian Haffner. This failed revolution in Germany can teach so many lessons. Of course the end of WWI in Germany was a huge crisis. Book: https://www.amazon.com/dp/B00DAN2E1W?tag=duckduckgo-iphone-20&linkCode=osi&th=1&psc=1 The book can usually be found online, PDF, free.

It ended up helping Right because the Left betrayed itself! Remember the internal self policing of the Left, say the workers, this is the Super Ego of Freud (the parent), and Freud directly addressed this issue.

Of course the street element fighting the revolutionaries, the Freikorps, was all external parent.

Later on, the Frankfurt School tried to understand why the Revolution in Germany failed. They incorporated Freud into some of their work. It is often forgotten that Erich Fromm was a fairly early member of the Frankfurt School.