Pardon my ignorance if this is a very, very old issue, but it appears to me that the stage 2 and stage 3 construction-only elements of the player stronghold (regardless of House) are never enabled. This might include scaffolding, construction materials and house pod buds (the Telvanni intermediate content is very cool). These require the global stronghold to be set to 3 and 5 respectively and this is not done by any script nor through dialogue. I just check version 1.6.5d of the unofficial patch and the issue is not addressed there.

The activators appear to be working – I set the value of stronghold through the console to check it out in-game. I suppose few players actually travel to their stronghold while it is under construction (particularly the rather isolated Uvirith's Grave and Bal Isra) so perhaps this is largely a moot point. However, if there is no intention of ever enabling them then they may as well be removed from the world and have a few less scripts running in those cells.

Personally, I would like to utilize them and if there has not already been some widely-used solution to the problem we could incorporate the necessary fixes in LGNPC Tel Uvirith and LGNPC Indarys Manor. However if the community agrees that a fix should be made then the unofficial patch, sorry... Morrowind Patch Project would be the best place for it.