* Let $Q$ be the homotopical category of combinatorial model categories and left Quillen functors, with left Quillen equivalences for weak equivalences.
* Let $\mathbf Q$ be the corresponding $\infty$-category (in whatever foundations you prefer).
* Let $Pres^L$ be the $\infty$-category of presentable $\infty$-categories and left adjoint functors.
* The usual functor from relative categories to $\infty$-categories (modeled however you prefer) descends to a functor $N: \mathbf Q \to Pres^L$.


**Variation A:** I'm happy to work with simplicial combinatorial model categories rather than ordinary ones.


**Variation B:** It would also be interesting to know the answer to the following questions for combinatorial model $\infty$-categories and left $\infty$-Quillen functors. This is probably easier because one has more flexibility in this setting.


**Question 1:** Is $N: \mathbf Q \to Pres^L$ an equivalence of $\infty$-categories?


This functor is known to be essentially surjective -- for simplicial model categories this is in HTT, I think.


**Question 2:** Can the homotopical category $Q$ be refined to a model category?


There are size issues here; I'm happy with any way of handling them. I might suspect that something like Dugger's universal homotopy theories provide cofibrant resolutions. More specifically, I'd like to know:


**Question 3:** Are there model categories $C, D$ such that every left adjoint functor $NC \to ND$ is modeled by a left Quillen functor?



Do combinatorial model categories and Quillen adjunctions model presentable $\infty$-categories?
As pointed out in the answer to [Localizing $\mathrm{CombModCat}$ at the Quillen equivalences](https://mathoverflow.net/questions/304399/localizing-mathrmcombmodcat-at-the-quillen-equivalences/405993#405993),
the answer to Question 1
is affirmative and is provided by the paper
[Combinatorial model categories are equivalent to presentable quasicategories](https://arxiv.org/abs/2110.04679).


