Boba housings are known to have tight-tops that restrict compatibility with non-OUTEMU stems.
Boba housings come with several top-housing choices. There are the tight “no slot” tops, which emphasize stability over everything [including lighting and compatibility.] However, the more lenient tops with slots for lighting typically allow for a greater range of compatible stems.
If you look into this issue, or contact the distributor directly, you may find that you can obtain Boba top-housings that allow you to use Gateron Brown stems.
Also, Boba housings are supposed to be pretty compatible with Cherry, so you could try Browns or Clears and see if they fit easier.
I agree with your alternative switch choices.
Some other ones to consider:
-Gateron CAP Brown V2: This is a more punchy Gateron Brown, more Ergo-Clear-ish. Once lubed, they produce a pretty deep clack on polycarb.
These would be a little more wobbly than Boba housings, and almost as loud as U4T. Good compatibility with lighting, I think.
-JWK/Durock Midnight: You can put a Durock Medium Tactile stem in a T1 housing to get a more tactile DMT. Similar to putting Gateron Brown stem in Boba housing. But this is probably more tactile, less pre-travel. [The factory JWK Midnight was somewhat more custom than what I am describing.]
-I enjoy Naevy 1.5, which is a smoother Ergo Clear. But many say that they are barely more tactile than Browns. Plus, as long-poles, they are almost as loud as U4T.
As for my experience with your alternative switch choices:
-Cerulean: I haven’t tried these, but used other DMT variants. They all need lube, for one reason or another. But they take well to aftermarket lubrication.
You can lube them with heavy 3204 / 205g0 as if they are linears. They will feel like buttery linears with a tactile bump. At least until the lube eventually reduces over time.
You can give them generous 3203, and they will still feel like Ergo Clear tactiles. The 3203 will reduce scratchiness and ping, but it won’t deepen the sound.
I found that mild amounts of 3204 weren’t very effective. Overall, the DMT has less pre-travel than one might expect or desire, but they are just big Browns once lubed.
I think that the Taro Ball variant of DMT was very nice. And could be made to sound deeper with 3204 / 205g0. However, I was using R1 produced during JWK peak molds. I think you can still find Taro Ball on AliExpress, but I don’t know if those ones were produced with optimal JWK tooling.
-Penguin: I found that the stems felt overly rounded while typing. It made the switch feel mild and boring. Plus, yes, they need probably at least 63.5 G on 1U keys and 67 G on the spacebar in order to return properly.
You can alternately replace the stems with MX Clear stems that have only been lubed on the tactile bump[!] This makes for a more interesting switch, in the opinions of some. Can get away with 60 G springs if doing that.
-Zealio V1 Redux: This probably has the stem shape you are looking for. The switch itself comes largely unlubed from the factory. It will make weird noises.
You can give most moving parts a consistent coat of lube, and that will reduce the sound issues. Some have found that only lubing certain parts produces a better key-press, we can talk about that.
With lube, I think you can get away with 60 G springs or so. It would be interesting to try these [at somewhat higher weights] in the Boba housing, but it may encounter fit issues as with the Gateron Browns.
You just missed the sales on Zealios, but the sales will probably come back around the holidays and boxing day.
But I like what you are doing with your project. I always felt that certain Gateron or Gateron-like stems could be ideal in a Boba housing. The issue is with fit, which may be solvable via the use of different top housings.*
I wonder if KTT Matcha would also fit the bill, being a medium tactile that probably isn’t long-pole. There were huge sales on them in November. They do need to be lubed to get deeper sound. But they may not have enough pre-travel, I can’t remember.
You may also want to look into Durock Light Tactile, particularly the Cotton Candy variant that uses nylon housings. It’s supposed to have characteristics similar to what you are looking for. But I, and some others, don’t like how the stem interacts with the leaf. And I feel as if there could be more pre-travel. BTW you could also consider lubed Blueberry Chiffon V2 as a kind of toned-down, medium-tactile U4T. But I doubt that pre-travel feels more than 0.5mm, if that.
*BTW I put Gateron Orange stems in T1 housings with 62 G 16mm springs, and it worked fine. Those are basically Brown stems, I think. It was a sharper, more abrupt bump than what you would get in normal Brown housings. You can use MX Clear stems with ~65 G springs.
You can even put MX Brown stems inside YOK Panda housings with 60 G springs. You may laugh at the “dirty Pandas,” but they have some of the characteristics you are looking for. Definitely needs to be lubed to address the outrageous sound they produce, but they are poppy, more-tactile Browns. I suppose you could try this with Gateron Browns, or even Zealio V1 stems.
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