Many posts speak of the wall you hit upon reaching Level 30 , the large gaps progressing up to that stage and a a desire for XP usage and pr outside of just rerolling your consecrations. I think we can push beyond a simple prestige system and reward the dedication by making the Level cap 100 and giving double feats at thresholds, an Exalted Feat at 100 and minor bumps along the way in between the big moments.
LEVELS 40-100
At Level 40 you can choose a second Level 5 feat
50 for 2nd 10th level Feat [or maybe an Elite Feat]
60 for 2nd 15th
70 for 2nd 20th
80 for 2nd 25th
90 for 2nd 30th
Finally at Level 100: you can select an EXALTED FEAT deserving only the most worthy of rejects!
Here are some example ideas based off what operatives get in their trees:
Vet: bottomless mags of auto crit bullets in VF, Coherncy +50% all weapon damage buff while VF is up OR nuclear grenades
Ogryn: coherency healing on charge, invulnerability for 0.5s per enemy bowled over by charge, Double Wounds, HP & toughness
Psyker: Dream caps at 300%, Triple Nade blast radius, Contagius head pops
Zealot: Your Special Ability crit explodes with holy fire, Melee crits max toughness for you and allies in 6m, Coherency Ultra crit buffs.
For UI, you need only add a second ‘train track’ looking line underneath the one already in the feats menu. under 5 is 40, under 10 is 50… so on until 90. Only when someone (eventually) hits 90 will there be a pull down to see a legendarily immaculate imperial UI showing your soon to be level 100 Status! Finally, once reaching 100, any XP afterwards is converted into bonus Diamantine and plasteel, Multiplier for each mission. Or since the levels go to 100, you could give a 2% resource boost every level after 30 - maxing to 150% at 100th level.
OPERATIVE PERKS
The above system continues the game’s power spikes in chunks over a long time but to help that grind have weight- There should be more build choices as you level. I propose every 2 levels, letting players choose a Minor Perk Buff for the class which scale each time it is selected and can be respecced in a menu. Even if the game stays at 1-30 Levels, this’d still be a fun addition 
Vet : +0.5% gun damage, 1% Reload speed, +2% Max Ammo/Mag size, +2% Grenade damage/Radius,
Ogryn: +0.5% Melee damage +2%HP/toughness, +2m Coherency size, +1% Damage reduction on toughness
Psyker: +0.5% Staff Damage +1% quell speed, +0.5% burst speed, +1% Blast damage/radius
Zealot: +0.5% Melee Damage +1% Attack Speed, +1% HP/Toughness, +2% Toughness Recharge.
When you go into operative menu, these percentage buffs can be slid up and down in a points system. Allowing you to easily swap minor perks around just like you can with the feats. Please note that the .5s,1s, and 2s assume this in conjunction with the Level 100 suggestion earlier. Meaning that by Level 100 you’d have a +/- 25,50 or 100 in the minor feats (assuming you max only 1 perk).
Another benefit of this: when Operative perks and Hadron systems in tandem- this means more of the full feats can be designed around encouraging gameplay styles rather than flat bonuses that would be covered by operative perks. Even if they are not reworked, would positively effect the design of future classes.
From a design perspective, the operative perks are not as easy to implement as Level 40-100. Perhaps the Operative perks can be made available as an NPC function of training if that is easier to implement- would give more reason to see Zola, or another character we never see out of cutscene
Ofc FatShark can rescale each of these numbers (or their intervals) but a slow growth beyond your gear and Feats that you can retrain without RNG would be so satisfying. Both systems should be implemented together so that when you are getting the Prestige 40-100 Level things, you are still getting the minor bumps to feel progress over time beyond the RNG consecration and other systems. I’m eager for comments and feeedback on these ideas that myself and friends have discussed for weeks as we swap and relevel characters
TLDR I propose adding Level cap 100, Double Feats every 10 levels after 30, Super Feat at 100, minor feats every 2 levels.