Hi, Joe.
1. ADFS is not quite "all-or-nothing" setup (unlike regular BIND, for example).
There are some applications (most notably MSCM and LM Rich Client) that do not support ADFS. For those Infor made a special provision, so they can continue to use BIND. This is done by essentially setting us yet another set of web servers/endpoints in LSF and LM with special service types that use regular LDAP BIND, like I assume you use now.
In theory some of the items you mentioned can go over these special services and still login to Lawson via BIND. As an example, we were able to use LSA to connect to that special endpoint, and it indeed logged in with the regular screens.
2. The main idea, however, is that ALL users, including EMSS, will use ADFS. That means ADFS web server used by Lawson will indeed need to be exposed to all users, including the ones logged in from the "outside" (if you allow login directly from the "outside").
3. The protocol is SAML 2.0. So you can definitely use non-ADFS user repositories, such as Azure, PingFederate and a few others, but there are additional requirements for these repositories. I suspect most people, if they have AD, will simply use ADFS.
4. I do not see any reasons of NOT using loadusers. HOWEVER, with ADFS you will get extra identities that you may need to load as well, and loadusers is not capable of handling those. So you will need to supplement it with ssoconfig loads (if you really need to do command-line user loads and not IPA, for instance).
5. Re announcement - here is my take on it:
In May, 2019 Lawson will stop testing or releasing any patches that are specific to LSasSTS. Nevertheless they will still support older ESPs that have this option. Note that Infor suports 3 last ESPs. So, since we have ESP10 out, Infor suports ESP 10,9,8.
Infor plans to release 1 ESP per year. So, in May 2020 when ESP12 comes out, they will drop support for ESP9, and that will be the actual end of LSasSTS.
In a mean time - after May 2019 if they determine that your problem is related specifically to LSasSTS and not something else, they may ask you to switch to ADFS to fix it. In my view it's an unlikely event, but anything can happen.
Re: benefits - the primary benefits of ADFS as I see them are:
1. Final fix for the timeout issues. As you might know, it is actually not technically possible to fix all of the timeout issues in LSasSTS in a complex installation that involves LSF, Mingle, LM, IPA, GHR, LBI and MSCM. There are specific situations when some components will timeout and others will not, thus resulting in WEIRD issues on the screen.
2. Lawson will not get/process passwords. You will be authenticating BEFORE you get logged in to Lawson
3. Two-factor authentication will be MUCH easier to do.
4. Some weird user-name-related issues will be gone, such as case sensitivity etc.
5. If you decide to host some applications with Lawson (e.g. CloudSuite financials) and keep some on-premise (e.g. GHR), you can use the same users and authentication to login to both.