"2-4 extra small grid blocks of headroom?"
There are two block sizes in the game. In SE1 you cannot mix block sizes.

Large-grid is 2.5m per side. Engineer about 2m tall so that works. Making a 2 block high door makes it a 5m tall door and nobody wants that.,

Small-grid is 0.5m per side. Need at least 5 blocks for an engineer. Then you have to worry about some of the blocks being in open state and others being closed and the game maybe not handling that right.

Edit: Could ask Keen.
https://support.keenswh.com/spaceengineers/pc/topics/all/status/all/category/all/sort/popular/page/1

I am not talking about block size, I am talking about taller doors.
I am apparently nobody though, for wanting this. Or nobo? because I specifically asked for 2-4 small grid blocks worth of headroom, not a full 2 block high 5 meter door on the large grids.

> Then you have to worry about some of the blocks being in open state and others being closed and the game maybe not handling that right.
If the game cannot handle doors being a little taller AT ALL, I have some esoteric door shape mods that can apparently teach keen something they have NO CLUE about working, or you are assuming the worst possible work would be done on this kinda mod specifically. I am not looking for someone to solve the broken airtightness system, I just want a little extra room on doors to be an option, anywhere.

One large-grid block is 2.5m high and engineer is 2m high that is 0.5m extra. If you want more, the size of the block cannot change because it then won't fit with the other 2.5m blocks -or- you have to remodel the engineer to be smaller/shorter.

Edit: Maybe I'm misinterpreting you. Picture helps. Blue and green are large-grid blocks. Red is standard large-block door. Yellow is a small-block doorway I made for scale. White is doorway with more headroom but you can't put anything above it because its the wrong size now.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3455049092

Again, OP is referring to small grid.

The large grid door is 2.5m tall with a 2.2 meter opening, vertical.

Both small grid doors are 2m tall with 1.75 meter opening.

Any of the mods that convert large grid blocks to small grid might include the door, but it feels a bit overkill (including the door) if you don't want/need the rest of the blocks.

I apologize. Lack of sleep and reading OP's opening statement incorrectly.

With the title of all grids that implied to me large-grid also.
Reported as a feature request some time ago.
https://support.keenswh.com/spaceengineers/pc/topic/sotf-small-grid-doors

Laughed when I read this. I had the exact same feeling when they introduced the small grid doors. BUT, using them gave me more room for an actual airlock. Still feel like I hit my helmet when I climb the ladder and enter the outer door.

These should all be 5 small grid blocks tall

Double Door Airlocks - new on the workshop:
https://steamhost.cn/steamcommunity_com/workshop/filedetails/?id=3454269412

Small Ship Mega mod Pack (by SEModder4). Has a few variants with or without weapons. Small issue with selecting a block. If the block is part of a group of blocks, the scroll wheel does not always work. You have to sdelect the large grid version first then place it on the small grid. Has the large grid sliding door and door.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=305329302

VCZ Doors. An older mod, some report problems. I use them in a few builds and they seem to work fine. Author is no longer active. Sliding doors, doors with ramps.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=856352904

You can also try to make your own. The following rover uses a learjet-style door that becomes steps/ramp.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1896885005

The door for the above was inspired by builds from LUCKYJIMBO's workshop:
https://steamhost.cn/steamcommunity_com/id/LUCKYJIMBO/myworkshopfiles/?appid=244850