There are two major problems with delves. The events are too long for all but the diehard and the faction runs are getting compounded by getting even harder, by tweaking of the rooms, and RNG 1 shot capable troops who scale up too large.
Rather than comment on that, as the OP asks.
For events, simple solution is allow for the option of the level that a pure faction run has been completed at to be the starting point on the Tuesdays. So if you have completed 200 pure faction in say All Seeing Eye, it can start at 200. If you have finished it at 300, you start 50 levels below. 350, 75 levels below. 400, 100 levels below. Nobody does pure faction really at any other tiers, and 400 probably is not commonplace anymore.
To allow people to farm, use a skip system for those not doing that, an option to buy in the Tuesday event at say Tier 5, to get the faction head start. Increase the cost of the Tier 5 purchase. (This could be any Tier, or you could even have an option in the shop so it’s not tied to tier to purchase the skip). Make that cost a high amount of gems.
This should help with player health and longetivity, maybe make them more inclined to pay for other things at other times. Gem stocks dwindle, it’s a choice rather than a given every time.
Additionally, in any new event, there’s a chance to buy a start of 100 or possibly 150 by the same skip method, at a cost of gems. Not going to comment on the cost, but it should be high. It will not interfere with new faction events and the game ecomony as they are one time only over a weekend initially. You must complete faction run at 200 in the main event to be eligible for the mode suggested when it comes round again on a Tuesday perhaps. This should be a system where everyone can choose, pay the appropriate costs in gems, and then make the faction efforts more likely within the existing system.
In faction runs, allow the chance to drop a ‘Return to Camp’ in the event, or buy it. As Delves was supposed to follow some kind of system not to dissimilar to Dungeons and Dragons type things, then allow the party to rest, heal up. Pay a levy to give you a chance to obtain a Camp drop before the event. Perfectionists can decide not to do that, those that want to succeed, the levy has to be steep to fit in with monetisation of game modes so that people do not stop doing those.
If you get the camp drop, you can take a timeout and are allowed to add/replace (if one dies) 1 party member from either the faction or the kingdom into the team, and get a 1 time additional bonus to your team, which is not game breaking, maybe an enchant all 1 time, or fortitude to all.
Furthermore, increase daily delves to 4 attempts, in light of the ever increasing factions and let that cost something for the 1 extra daily delve. It could be currency, but another idea I thought of was maybe in a new treasure map feature, you can earn 1 extra delve attempt by doing something in there, maybe 2 vaults. 1 time only.
Finally add a button in the pure faction of a potion icon to show it was completed with potions. If the camp feature is introduced, add a bonfire icon etc.
Edit - If it’s felt that the option makes it so much easier to complete factions too swiftly, increase the level disparity, to maybe an extra 50 levels difference. So, even at 300 completed pure you only get a start at 200 etc.