I just read about the Stellarmate X, which seems to be a Mele 3Q or something like that with Stellarmate on it.

One question: since I have a stellarmate licence but use Kstars on Mele 3Q (due to speed ) would it be possible to use my Mele 3Q with the Stellarmate App in the future? Would be really great!

From Facebook page today :

- Will there be stellarmate image or installer for x86_64 for those who bought the OS?
- Not at this stage, but we plan to provide it later.

That would be nice! I was thinking of moving from PI to Mele...

The Pi4 with sufficient RAM and running Stellarmate from SSD is perfectly fine, imho.
I never expected desktop PC -like performance on the Pi4, though it's a real difference compared to SDHC cards, also boot time.
And i use LAN instead of WiFi, if possible.

Yes. That's the problem - "sufficient RAM".
I have two RPI's and they are both 4Gb RAM.
They work OK but with my ASI2600 I have to use some limited settings (like no debayer for fits viewer, etc).
8Gb RPI's are hard to come by these days...

I just bought a Mele 3Q with 8Gb of RAM.
Installed Ubuntu Mate and all the astro stuff.
All seems to be working fine.
Waiting for the weather now to do a real test. Will be bad for a week or more.

When Stellarmate will become available I will certainly give it a try.

I switched to a Mele Quieter 3C, which has been working well for me with UbuntuMate. The 8 G RAM helps, as does running off an internal SSD. Only thing I struggled with, and got help with, was setting the machine to auto boot rather than using the power button.

It looks like StellarMate X OS will be available soon. Product Available Date: 2023-04-13
That would be great.
I plan to switch to x86 and want to use the app on my tablet.
Side effect: I can support the development by buying the license.