Simplified romanisation approach for Gothic, what is your opinion?

Yes, that's one change. Sorry, I took the liberty and changed it.

The second change is more radical, reformatting the way Template:ja-romaji works where a definition line with # is generated by the template.

A shorter (one line, one template)

{{got-romanization|𐌲𐌰𐌱𐌰𐌹𐍂𐌰𐌽}}

is to replace (two lines, two templates)

{{got-rom}}

# {{got-romanization of|𐌲𐌰𐌱𐌰𐌹𐍂𐌰𐌽}}

BTW, I have copied some logic from the Gothic template Template:got-romanization of but struggling to make Category:Japanese romaji without a main entry work in Template:ja-romaji.

Please check this version of "afdrausjan", which uses Template:got-romanization, which uses the same approach as Template:ja-romaji - the definition line is generated by the template and can only provide a link to the main entry. Is it one to one in Gothic, i.e. can one romanisation have more than one main entry, if not, how many would be sufficient? We have given 6 in Japanese.

I don't think you should discuss that with me, because it seems like a very fundamental change to WT:ELE that needs a lot of discussion and consensus. Aside from that, some bots like AutoFormat assume that definition lines begin with #, and expect there to be a headword, so they would break with such a change.

The generated definition line has # at the beginning of the line, so it doesn't get picked up as fundamentally different by KassadBot (AutoFormat). That's the case with Category:Japanese romaji. The vote on Wiktionary:Votes/pl-2013-03/Japanese Romaji romanization - format and content is on.