This userscript adds a panel under upload page, which is able to open upload page on different booru and prefill almost everything.
For example, left window content I filled manually, and right window content was formed from it.
Script has an ability to try to respect tagging rules of other boorus by converting rulesets if rules are different, but, of course, it's impossible to cover everything. Check tags before hitting "Upload", please.
ATM only Philomena boorus are supported. BoR-based boorus are supported partially because of less amount of data for tag analysis.