Ok, messup that turned out semi-ok, considering how poor the impression and negative were.

The tubes fell off (were pushed out by the IEM) and the hole happened to be too wide for RE-400 nozzle it was planned for.
The ear canal parts are actually completely missing, as the tube is too large diameter to allow any reasonable quantity of silicone to pass down.
Demolding silicone from silicone was about as hard as previously, maybe slightly easier. Mostly hard because of the irregular surface on the sides of the mold, which were incompletely covered with the unsealant. The ear part actually demolded very easily, meaning Ease Release is essential.
The slightly harder silicone (Shore A 30) is about the same hardness as the one used in SE-5.
No bubbles in or on the positive, which means this silicone is suitable for accurate molds, both negative and positive.

I didn't bother to round out these "broken"impressions, just cut off the excess with rough knife cuts. The cuts were a bit tricky, the silicone is highly elastic and there was lost of excess.

Short version of the result: Generally similar to long tips, except more comfortable (still not superb due to bad impression) and way better at soundstaging. The. Best.
Balance is reminiscent of very deep fitted Brainwavz B2, except not "sparkly", instead bit "hot", much better upwards extension, no bass boost.

And now for the good part - the IEM sounds very closely to equalized with these "tips" or rather mounts, once they fully seal. Better soundstaging in fact, reminiscent of the other CIEM without its weaknesses. Isolation is not great, on par with EtyPlugs, bit lower in mids and bass, higher in highs. The silicone is very acoustically transparent in this small amount.
Some 4k hot boost is apparent, perhaps could be tamed by the return to original filters as well as another high freuqency peak (14k?). Air is better than even the equalized. It is semi-shallow insertion. (-3mm? I'm not sure whether to measure from the nozzle or the target tip position.)
It is tricky to put these "broken" impressions in so that they fully seal, but they hold well once in, right ear much worse than left - does unseal at times; not entirely comfortable either, on the tragus - I filled that area in as there was a hole. (Remeber that was with that terrible clear material.)
Bass is highly "thumpy" but more of "pressure" kind than "ear shaking" or "bone conduction", which means the bass is likely balanced with exellent subbass, without typical 36Hz boost.

And pics. I've actually pushed them in bit deeper than shown in these pics. The in-ear one shows almost the correct depth.
EDIT: few more cuts fixed the comfort and improved seal. Cut based on the better impression (rather than my guess) improved things further. The main gain from the better seal is that the IEMs sound bit bassier still ("kickier" but not boosted) and faster? 4k/14k resonance was reduced notably - that was probably the leak resonance. The sound is way faster than with all other tips and now I can put them in reliably. Gains in soundstaging again. W/o crossfeed, they sound binaural-like, with crossfeed, like an excellent, slightly bright, set of speakers - monitor-like. (No equalization yet.)
Still, will make new ones based on the good impressions for comfort and better seal. I'll use 3mm silicone pipe to make the hole instead of trying to actually use it as the canal.