Dear Bratislav,
I'm also have about 20 years practice in making mirrors for telescopes And i also would thinking and thinking to make or not to make mirror with ratio less then 4. But you should agree your demand on mirror's quality is much more stronger then for a biginner. Yes, I'm agree with you my friend is talented man and his task was more easier then I gave him 8" optical flat for testing the primary and the whole telescope.
May be I'm wrong, but for me to make a GOOD mounting is more difficult task. Taking into account the question was about a portable telescope I've wrote my advice.
Trully, Alexander