Efficiently rendering a large number of "select" elements

I'm writing a web application that displays a large number of rows of data (~2000 at present), each of which has a drop-down "select" element with ~100 options. Any of those options can be selected by default. I'm generating all the actual DOM elements client-side. My problem: rendering this beast takes ~4 seconds on my relatively recent machine, which is really suboptimal. I know the problem is specifically with all the select elements, because replacing them with a bit of static text or a single-option list causes render time to be nigh imperceptible.

The vanilla code, minus failed experiments (see below) is here.

Avoiding the suggestions of "paginate your data" and "don't have so many options in a select", what is the most efficient way I can write my append / render code, assuming I do have a legitimate reason to display that much data and have that many options? For my purposes, Firefox is the only platform I care about.

Things I have tried:

Using an async loop to append rows to the table (slower than a regular loop, and oddly didn't render the intermediate results)
Building up a string that represents the body of the table and inserting it into the DOM in a single call (almost identical performance)
Instead of inserting the entire options list, inserting a single-option "select" element, and then populating the entire list when the "select" element gains focus (presumably because someone is trying to change it). This was actually pretty high-performing for the initial render, but then populating the element with the full list caused some weird behavior, losing focus and never actually being able to "open" the select element.

Right now my default assumption is that the third option is the way to go, and I need to figure out how to do some bookkeeping about what has already been populated. But my suspicion is that there is a plainly better / faster / more idiomatic way to do this. Is there?

Solution

Yes, I would "lazily" generate and/or populate the dropdowns.

That is, only create and populate the dropdowns when the user clicks on them, as probably almost all of the dropdowns in the 2000 rows will never be used right?

Perhaps a select element might not be the best UI here too, but instead some kind of HTML menu like so: https://jqueryui.com/menu/ that is created, populated and displayed only when the user clicks on some kind of button to display it.