[Samsung Galaxy S10/S10+/S10 5G/E Cross Device Deve] human_io:
Thanks to everyone for your help. Decided to try my luck all over again from the very beginning. Forgive the long outline but as everyone has been so helpful I wanted to outline my process in the event it might help someone else, even if I am unsuccessful in this attempt.

Part 1: Flashing Required Firmware G970FXXS5CTD1

Downloaded Frija V1.4.2 (this will be used to download latest firmware

In Frija I entered SM-G970F as Model and MXO as CSC (this may be different for your needs, not sure how much this matters)

Downloaded firmware G970FXXS5CTD1_CL18242812_QB30535771_REV01_user_low_ship_meta_OS10

Turned off phone.

Hold volume down button + bixby

Insert USB cable

Open ODIN 3.14.4 as administrator

Flashed firmware G970FXXS5CTD1 by loading AP, BL, CP, CSC, and HOME in each slot.

Received PASS!

Part 2: Confirming Correct Firmware

Phone Rebooted

Phone initially didn't boot into stock and rebooted itself to stock recovery

Selected format device in stock recovery

Phone rebooted

Samsung logo appears for about 1 minute (felt like a long time)

Eventually Successful booted into stock

Confirmed stock One UI 2.1, Android version 10, Baseband G970FXXS5CTD1, Build QP1A.190711.020.G970FXXS5CTD1

Unlocked developer options

Confirmed OEM unlocking (bootloader) already unlocked

Allow USB debugging

Part 3: Downloading Preparing TWRP, VBMETA, and Lineage OS Rom Files

Redownloaded vbmeta and twrp 3.3.1 beyond0lte5

Unpacked twrp image

Renamed twrp to recovery.img

Renamed vbmeta_disabled to vbmeta.img

Added twrp and vbmeta images to 7Zip archive as tar, compression level store

renamed new tar file to recovery.tar

Redownloaded lineage os beta 2 zip

Placed lineage os beta 2 zip in phone sd card

Part 4: Installing TWRP Recovery

Turned off phone

Held volume down + bixby button

Connected USB cable

Launched Odin 3.14.4 as administrator

Loaded recovery.tar in AP slot

Under options tab deselected Auto Reboot (f. reset time still checked)

Receive Pass!

Part 5: Installing Lineage OS (and Gapps if preferred)

Reboot device holding volume down and power button for 7 seconds

When the screen turns off immediately press VolumeUp, Bixby and Power), and keep holding it, until the secondary warning appears (The one with warning about unlocked bootloader), then release Bixby and Power, but keep holding volume up, until the TWRP logo is seen.

Successfully boot into TWRP

Swipe to allow modifications

Select Wipe/Format Data/YES

Reboot to recovery (select do not install if TWRP asks about installing the TWRP app)

Swipe to allow modifications

Select Install/SD Card 1

Select lineage os rom

Check zip signature verification

Swipe to confirm flash

Flashed pico gapps (may end up not using these at all but wanted to verify they work)

Wiped dalvik/cache/data

Reboot system

Lineage Boot Screen appears

Successfully booted into Lineage OS! (as others have stated the Boot screen should last no more than a few seconds)

Thank you to everyone who helped along the way! I'm not sure if downloaded files were corrupt or if I took a misstep but I hope my experience might help someone else coming from stock! Excited to have a "small" phone, with great hardware, and finally great software!