I have a situation where a router with an LTE modem might be an ideal solution.

But, service provider compatibility, SIM cards, data plans, etc. might be show stoppers. Is there a page with an overview of these topics and links to more detailed information? So far my searches have only turned up folks discussing issues after they have gotten past this point.

service provider compatibility

not ISP but LTE Bands your ISP have should be supported by your LTE modem.

SIM cards

Yes, they exist and we use 3 differ size in differ devices. Check limits.

data plans, etc. might be show stoppers.

Check ISP offer, probably it's on it webpage.

Is there a page with an overview of these topics and links to more detailed information?

Infoline of your ISP? Wikipedia with list of bands per country? Google? Your government institution of RF stuff?

So far my searches have only turned up folks discussing issues after they have gotten past this point.

What point?, You not ask properly even one question yet.

Here are some examples from searching the MikroTik wiki:

viewtopic.php?f=2&t=166151&p=816869&hil ... an#p816869

"some mobile operators play silly games if your "plan" is for a mobile phone and you use the SIM in a router. "

viewtopic.php?f=2&t=158983&p=800508&hil ... an#p800508

"Solution: not use a SIM card who have a Plan for MOBILE.
AT&T detect some IMEI (lte modules modems) and just not give them internet because they are not MOBILE.

Buy a "Tablet Plan" who will be working. Working at more bad bands and that's why we move to Sprint who merge with T-Mobile and this will be best deal to use."

viewtopic.php?f=3&t=162160&p=799383&hil ... an#p799383

"I have a tablet SIM, and it does work just significantly slower in the LTE6 modem than in the LTE-US modem."

viewtopic.php?f=2&t=160297&p=788013&hil ... an#p788013

This is one where you acknowledge experiencing the kind of problem that I worry may be a show stopper.

From all you answers I only guess your are from USA?.
Still, I am from Europe :), about USA ask FCC, your ISP, your ISP forum etc., Like I to reach information.
You not ask question but write a generic sentence.
Start be serious.

Just like SiB answered, most of these questions are for the mobile operator. This is a global forum, so we don't know which country you are from, what operators you have nearby etc.
MikroTik manufactures devices where you can use any operator or SIM card. Just check if your operator works in the supported frequency.