Probably a little late to add anything like this next season but a potential idea for future content.
Seeing as bosses have been around for a few seasons now, and just aren't viable due to the difficulty of balancing the rewards, why not replace them with something like an envoy event?
The event would occur every 4-6 hours or however often you deem fit. It would occur in the player event spawn area. Players would join with the /join event command. The amount of crates that drop would be based off how many people used the command. Ie. 10 people would spawn 20 crates, 50 people would spawn 100 crates etc.
Rewards would include things such as crate keys, augment boxes, scroll boxes, booster boxes, attachments, generators, small sunbits rewards, money/tokens rewards (scaling with the system described below). Basically the current loot you can receive from current features like postman/cargo/lootboxes
The scaling of the rewards would be changed to coincide with the lootboxes releases meaning there will be 3 tiers of envoys. Week 1 would obviously be the worst quality. Where if a player opens an envoy crate and they receive a booster box, the chance of it being 1.25-1.5x is much higher with a 5x box being very rare. The next tier of rewards would be released after the first week of play alongside the tier 2 lootbox, then the tier after in week 4 with the seasonal event. The envoy crates in week 4 would have a much higher chance in giving higher quality rewards, higher boosters, better quality scrolls, higher tier gens etc. etc.
Obviously altering the chance of rewards will probably add another hour or so of maintenance work for a few weeks of the season. But I think the bosses either need to be removed or have their rewards reworked. Newer players especially will dedicate a lot of time to try and complete one and get totally scammed once they discover how bad the rewards are and rather than just completely remove a feature from the game, it might be better to replace it with something else such as this.
Not sure how viable it would be or if you'd be willing to spend the time/resources with updating these a couple times a season.