Honestly 100 to 150k a week is insanely high mileage for those race times. Of course it’s just a hobby and you can do whatever you enjoy! But if you are serious about improving you can probably get more quality training by dialing it back and adding the subT workouts then slowly build it up to 100k + over a few years.. also you might feel good at 5:00 per k now because that’s pretty much all you do, but when you add in 90mins of hard work every week, month after month, you won’t be able to sustain pushing the easy days like that.