the behaviour is not limited to the Vega lineup .... I've had it to one degree or another since I got rid of my nvidia 460 gtx ... I went to a gtx 760 ... suffered underutilization hard .... got a 4K screen ... then a gtx 1060 .... then a ryzen 1600x ... and yeah, back to underutilization ... with my screen I'm pretty much stuck using 60hz, ie 60 FPS, with vsync .... video load 'currently' tends to be between 40-60%, depending on how much of the map I'm viewing .... im thinking on a vega series card, if your not pushing 2K, your probably not forcing it to use enough of its graphics power .... using a 'fullscreen window' its possible to exceed your monitors maximum resolution, its a little bit of a balancing act, and you can totally take it too far .... my 1060 DOES NOT like doing 8K, and up around 16K I was getting about 1 frame every two seconds, not very enjoyable ....
through the use of a user.cfg file, I run a mix between high and low settings, everything in the game settings is set to low, and I turn up the options that I want included, running a user.cfg file to customise things, is completely within the rules, most of the options that would give you an outright advantage, are not modifiable, and those are not the only ones that are locked out from usage, and then, with relation to some values, what you select wont matter, because when you join a game, the server can 'force' keys onto you that suits them .... so, generally speaking, as long as you dont go outrightly mental trying to cheat an advantage, your pretty unlikely to find your way into trouble ... beyond that, theres a rule, and a method you need to be aware of, a user.cfg file is explicitly allowed, and thats where you should keep your customisations, for compliance to the rules, and the method relates to a second file, called 'tuning.cfg' which simply contains the line 'exec user.cfg' .... normally, the user.cfg file is only read once, before you enter your login details, and a good chunk can become irrelevant before you get into the mechlab ... the tuning.cfg file is called, when you spawn or when your released from a dropship ... this will cause a delay at that point, vastly reduced by jumping into the testing grounds, before going into a live game .... please also note, that your user.cfg file is included with any sent through crash dumps ....
to create the files, find the main directory location like "C:\Program Files (x86)\Piranha Games\MechWarrior Online" for the default standalone version, you should have a file called game.cfg present, copy and paste that file into that directory, and it will make a copy, then rename the copy to be user.cfg and repeat for tuning.cfg, be aware, that by default, you wont see filename extensions so easily, and thats why its easiest to copy paste the existing game.cfg file ....
anyway, try adding these to increase the GPU load :
e_Lods = 0
e_TerrainLodRatio = 1
on a ryzen (or intel 4th/5th etc), you might benefit from disabling the jobsystem
sys_job_system_enable = 0
also, you might benefit from keeping all threads on one CCX ... seems to improve my minimum frametimes, but as I'm on a 1600 and I disable SMT, I'm only assigning the game 3 'cores' @ 4ghz ...
for a 1700/1800 with SMT enabled, use 'back' 8 cores
sys_affinity = 65280
for a 1700/1800 with SMT disabled, use 'back' 4 cores
sys_affinity = 240
for a 1600 with SMT disabled, use 'back' 3 cores
sys_affinity = 56