My only concern is that the people who run the tools etc. have their political view. For example " https://tacticalvote.co.uk" is clearly against the Conservative party. So that tool is straight away biased.
Think about the name... You have to vote tactically against something ergo someone
In this case - FPTP - the tactics are to identify the (usually two) candidates that most plausibly could win in your district and pick from those, ignoring all other candidates. If Apples win with 310 votes and Bears had 290 votes, those Apple-haters who gave Cheese 60 votes to come in a distant third are kicking themselves.
For many (millions of?) voters in the UK the idea is to achieve a specific outcome on a single issue (Brexit) which is not actually on the ballot at all, so tactics come into deciding how to vote so as to make your preferred outcome more likely to occur.