Maybe I’m getting you wrong - but what about:
{{- $.Scratch.Set "myLimit" 0 }}
{{- range $name, $items := .Site.Taxonomies.tags }}
{{- $.Scratch.Set "myLimit" (add ($.Scratch.Get "myLimit") 1) }}
{{- if le ($.Scratch.Get "myLimit") ($.Site.Param `tagsLimit`) }}
<div class="tag">
<a href="{{ $.Site.BaseURL }}/tags/{{ $name | urlize | lower }}" class="tag-text">{{ $name }}</a>
</div>
{{- end }}
{{- end }}
with config.toml
[params]
tagsLimit = 5