the steam version will prevent u from running multiple game instances. You need to go to everquest.com and click 'download the game' in the top right. after you download and patch the game to the newest update you can find everquest.exe in the EQ folder wherever the game was installed.
Right click everquest.exe to make a desktop shortcut. Right click the desktop shortcut you just made to select properties.
Find the Target: line.
In that line add 1 space to the end. Then type: patchme /login:AccountName
instead of writing AccountName insert the name of your login. this will let you bypass the launcher. repeat this for each account. for example mine looks like this
C:\Games\EQ\eqgame.exe patchme /login:Leicesismore

repeat this for each account you are using, making a new shortcut and such. rename the desktop icons to stay organized.

If a new update is available it will tell you to exit the game and run the launcher. So you will only need to run the launcher occasionally. Updates occur every few months i estimate.
For those that are curious; you can multibox using the launcher and skipping the above steps, but it is much slower to launch. This is because you can only have one instance of the launcher running at anytime. You must load the launcher and select the proper account then wait for the game to launch. Then close the launcher and re-open the launcher to then launch the next account.
The launcher may be viable though if you use account passwords that are cumbersome to type or are difficult to remember. The launcher will remember the account passwords. Also, you may not notice a difference in load times if you use a slow HDD. I use an NVMe SSD so the bottleneck occurs for loading the launcher which requires requesting data from the EQ servers.

for reference each game instance at a minimum requires about 1x 2012 or newer cpu core/thread, 1gb of RAM, and about 200MB of GPU memory. However, 2 threads per instance is recommended since this game is heavily bottlenecked by the cpu and/or cpu cache size. GPU requirements are nearly non-existent. running 6 instances on an integrated HD630 is handled while only partially loading the GPU.

i forgot where i found this info, I have it memorized now. but i will give credit where it is due if anyone can recall the original guide.
The cpu and gpu requirements are derived from personal experience.

multiple accounts are not necessary, it just allows you to do party based content like the original game was intended to be played. Most active players are focused on the end game content which requires the latest expansion. However, the first 25 or so expansions are free to play.