I appreciate you attempting expansion, I will say it is still difficult when you’re asked for specific detail and your response consistently States generalities like:

“lack of support” - meaning what, feature isn’t there at all? Doesn’t display existing tables from uploaded excel docs?

“has serious issues” - meaning… what are they?

“results in issues” - …

“…is borked” - c’mon

and "incredibly slow " - relative to what? Double time of expected from excel? Triple? Extra two seconds per attempt?

You’re using subjective terms that mean people can’t A) determine if you’re problem will impact them as well and B) you’re not describing your perceived issues well enough to allow experts reading along here, now or in the future, to offer you actual solutions or alternatives.

That considered, it makes you come off as a person who doesn’t want their perceived problem solved.

Probably more credibility if you actually give real, specific examples of what you cannot do on Libre Calc that you require?