This is a suggestion of improvement, ditching the need of cookies in search engine queries.
It would be great to be able to add information to the search engine URI of those listed (and later added) as search engines in Vanadium. If search settings are adjusted in the search webpage it is saved in cookies and forgotten on deletion, and in incognito the searchpage settings are default standard in each new session.
As an example I use this string of extra queries on my computer when using my default search engine Qwant:
https://www.qwant.com?theme=1&hc=0&hti=0&vt=0&b=0&s=0&l=en&locale=sv_SE&home=daily&si=1&c=blue&ch=glasses&eco_suggest=1&q=%s&t=web
Edge Chromium on PC lets you set separate default search engines for regular and incognito use respectively, and you can also edit the extra syntax into the URI. Country code, theme, safe search on or not, etc. I love it.