Article on language ideologies in relation to International Sign is out, and open access! "The tipping point: on the use of signs from American Sign Language in International Sign" https://doi.org/10.1016/j.langcom.2020.06.004 Summarised in a blog I posted a year ago: http://mobiledeaf.org.uk/aslis/ Thread

Discourses about the nature of IS are entangled with discourses about international uses of ASL; firstly, about the use of ASL versus IS as global deaf lingua franca, and secondly, about the use of ASL features in IS.
There is a lot of ASL in IS”, and“ That does not look like IS to me, but rather ASL”, are commonplace complaints. Overuse of ASL in IS is often associated with linguistic imperialism and judged as counterproductive for IS to flourish independently from ASL.
People estimate percentages of ASL in IS; e.g., 30%, 60%, & use labels for mixes: International ASL(IASL), strong ASL [in IS], IS with ASL flavor, ASL light, and so on (these labels do not necessarily refer to the same usages.)
While International Sign (IS) is a practice of translanguaging, it is often *treated as a language* even if people do not call it a language: as a contact language which is subject to language contact with American Sign Language (ASL).
Maintaining boundaries leads to linguistic prescriptivism aiming to curtail ASL use in IS. These include using non-ASL lexicon, and investing in what is called “visual”, “iconic” or “transparent” language use.
However, participants recognized that it is practically impossible to fully remove ASL from IS, not to slip into ASL, and that the use of ASL features in IS can be useful and practical eg. for specific terms as well as widely known signs such as "IMPORTANT"
Thus, participants imagined there is a tipping point between an acceptable amount of ASL in IS, and too much ASL in IS. The difficulty though lies in pinpointing this tipping point, partly because people disagreed on what exactly constitutes the use of ASL in IS.
Being anti-ASL can also be oppressive towards people who feel unable to curtail ASL in IS. Also, people may be unaware that they use ASL in their own IS and yet are pressured to reduce it. Linguistic prescriptivism may not be morally just in this context.
In summary, prescriptivism and translanguaging can thus go hand in hand. People want to protect IS by treating it as something fixed, which seems to contradict the ideology of flexibility that is underlying International Sign.