EDIT

WGB:

I actually did not read far enough to see that passage, only the examples citing nothotaxa, all without space.
I agree that inserting a space makes sense, especially with H.3A.2. in place that allows the letter x.
Perhaps we should suggest to the Editors to modify at least the examples in that way, to avoid dumb misinterpretations like mine (sorry).
Its yet another point making name matching tedious.

RG:

The code says “The exact amount of space, if any, between the multiplication sign and the initial letter of the name or epithet should depend on what best serves readability.”
There was a lot of debate at the Vienna conference on this where I and the RHS proposed to make it mandatory to have a space so there was clear guidance (and avoid emails like this) but because a book had just come out with lots of hybrid names without a space, one delegate blocked this, so it is still a free for all.
The space just makes it a lot clearer e.g.

Aconitum ×anthora

Is that Aconitum xanthora or Aconitum × anthora ?
Especially for non-experts and on phones it can get very confusing so I have always had a space (even when I typed with a type writer).
But you can do what you want under the current ICN.

RH:

ehrlich gesagt bin ich nicht davon begeistert, die Sache handstreichartig zu ändern. Herrn Govaerts in Ehren, aber manchmal schießt er über das Ziel hinaus (siehe etwa seine Vorschläge zur Änderung des nächsten Codes), und ich finde die Hybriden bei EDIT typographisch bisher mustergültig gelöst. Für manche mag das nun Neuland in den Portalen sein, aber auf der Zypernseite sehen sie seit über 10 Jahren wunderbar aus. Man besuche die Orchidaceae, etwa Ophrys oder eine hybridogene Gattung wie Orchiserapias.
Die Diskussion erinnert an das Weglassen von Leerzeichen zwischen Initialen und Familiennamen(kürzeln) bei Namensautoren, was ich ebenfalls grauslig finde. Da gab es doch eine optionale Lösung, oder?

AM:

after having decided very fast on the space after hybrids signs this afternoon in the meeting we received a mail from Ralf Hand who doesn’t like the new formatting so much.
So the question is how to continue. Unfortunately it is currently not yet possible to have project based formatting rules in this context so simply allowing configuration is not a solution for now.

Walter you mentioned that you consider this being urgent. Is there a reason why? If it is only for name matching to external resources a preliminary solution could be that we only format it according to the new suggested rule in the export. Just like we do with spaces in author abbreviations.

RL:

the ICN Article uses nothotaxa without space for species hybrids and with space for genus hybrids:
https://www.iapt-taxon.org/nomen/pages/main/art_h10.html?zoom_highlight=nothotaxa

There is no provision in this article about a flexible use of space so in theory the example of the Code has to be followed.

Common sense would be to use if WITH space in both cases, since one should not directly connect Latin name elements with other elements. Without space can potentially be confusing if typesetting uses "x" instead of the multiplication sign (as the latter is a special sign not usually available on a keyboard. In the example below for instance "Aconitum xanthora". In this respect I agree with Ralf. Why the Code has it without space is unclear to me. I checked previous versions of the Code and until the 1956 Paris Code it was cited WITH space and starting with the Paris Code WITHOUT space. Perhaps something to ask Nick?

NaK:

I think that the strongest arguments are established standard or conventions, interoperability, and compatibility with other databases, IPNI, WFO etc. We shouldn’t do things differently than the rest of the world and if IPNI, POWO and WFO do use the space between the hybrid cross and the epithet, we should do the same.
And I agree with Robert, not having a space is rather counterintuitive, can be confusing and does not enhance readability.

The new taxon pages may allow more configuration possibilities.

NoK:

As correctly mentioned by Rafaël Govaerts (cited by Walter below), the Code actually does permit a flexible use of space between the multiplication sign and the epithet, see Rec. H.3A https://www.iapt-taxon.org/nomen/pages/main/art_h3.html.

Although I also like the current way hybrids are displayed in the EDIT Portals, exports of data into other databases are in my view an important argument to have a solution avoiding ambiguities.

As the amount of space is flexible, using a fraction of a space between the multiplication sign and the epithet (but a full space in formulae) would be an option. If I understand it correctly, unicode provides different widths of space (see e.g. https://www.compart.com/en/unicode/category/Zs).