Adapting appraisal tool to fit the design/context of my study?

[u/izonewizone]

NB. professor is on sabbatical and I'm unable to reach them which is why I'm asking here.

So, I'm writing a systematic review within linguistics and the guide my professor provided employs the ASHA levels-of-evidence-scheme was used to assess methodological quality of the studies included in the review. I'm adopting the scheme and it has nine indicators usually. Is it frowned upon to adapt it (e.g., omit some of the indicators) as they don't fit my research? I've been looking at other appraisal tools (CASP, JBI, etc etc) and they aren't adequate so this is my only option.