So, this might be a controversial idea but, I believe that keep inventory on sieges should be re-enabled.
Why?
First, lets look at the set economy.
At this stage in nations, regardless if you drop a set or not, well established nations have huge stockpile of sets.
Alongside the new gun update (which makes people actually wanting to invest in a nation in the server and invest their time because they feel like they have a chance), if keep inventory in siege zones is turned on, it would give new nations even more incentive to actually try fighting their way, because you do not lose sets, thereby keeping the geopolitical landscape alive.
Only exception would be netherite tools, because they are valuable and I believe that they should drop since they are the only loot worth pursuing (unless they have a binding rune) so they should drop (in siege zones) (I do not know if this is possible to implement).
Set repairing is done by duct tape which takes resources to craft unlike mending, and if you take a set durability hit when you die (like which was suggested in N2 beta), it could lead to equipment being popped when you die and respawn, so you do still have the risk of losing a set.
Secondly, servers with keep inventory on in siege zones are WAY less toxic on their own nation members by others, since dying is not much of a deal and is affordable. Points are not much of a hassle anyway in a large siege, and I believe its time that CCNet also tries this method and it would curb a substantial part of toxicity from either side, either towards their own members or at others. This is one of the main reasons I do suggest this as well.
Zaify I recommend you to try at least testing this out in a major siege (since on test server no one wants to do major sieges :/), and give this system a try (neth tools should still drop imo, its your fault if you take it anyway (if you don't have binding on them). I'd rather have a less toxic server where people can actually do something (alongside the new gun update) instead of a server that is toxic, restrictive on new people just for the sake of a "set economy" that is already pretty broken anyway.
Also if you want sets anyway, go raid people or fight in wilderness or chase them away from the siege zone, its not like people don't do these regardless if they get sets in sieges or not.