Thank you Gabriel for the follow-up! Here are my answers to the requests. Sorry it's a bit long, but I hope these answer your questions adequately. I'm including 5 examples here to show its utilisation in a variety of ways. All of them are in runes, transliterated. The first line is the signum, second is a transliteration as found on the inscription, third is expanded, and fourth is standardised. a. is quite straightforward in Old Danish, with the d being shared between gud and drotæn b.-d. I'm including...
No the k there would certainly not look differently. As you say, the difficultly is indeed in the tokenisation and in any eventual possibility for analysis, and I was wondering if a similar solution to the ligature with <link> could be used (which is why I was thinking about ligatures even though it certainly is not one). However your solution with crasis could certainly work, although perhaps I might have missed it in the guidelines. Thank you so much for your response!
Expansion to the ligature guidelines
Marking transitions in language and/or script in the text