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The decomino itself makes a queen bee and unfortunately a tub, so a preblock is needed.

19-cell queenbee shuttle predecessor:

I don't think it is worth making an entire topic for this...

All patterns that fit within an (I think) 6x6 bounding box have been enumerated, so at 4x4 it's definitely a rediscovery.
@towerator agreed... I mean, the following is also a 19-cell queen bee shuttle predecessor.

To answer your question, I'm not sure if it's known. While it is interesting to see that decomino evolving into a queen bee, I think these kind of patterns aren't searched for, as it wouldn't help much in other projects where you want to build a queen bee. Reasons are:

1) The usefulness of a seed is that it can build an object anytime.
Seed often refers to a quiescent pattern that builds a particular object when hit by a glider.
So technically, your pattern (unstable) is not a seed. (Correct me if I am wrong)
A quiescent seed can wait until a glider arrives and build the object anytime, while the decomino can't.

2) There are already good seeds of a queen bee out there, namely: 3) The precursor is better if it is easy to build or is common.
Your particular decomino doesn't seem to appear often or imply a reasonable synth, especially compared to the QB seed in 2)

towerator wrote:I don't think it is worth making an entire topic for this...

I agree. I think your posts, especially if it's a question, would be more appropriate in 'thread for your unsure discoveries'. You can enter a thread and click 'postreply' to reply to a post, in case you didn't know how to do that.