It depends on how strongly I feel about the issue. Like for your example yung nag endorse ng occupation against Ukraine, most likely I wouldn't attend it too.
That also goes for your other example when something is endorsed by a blatant racist. I feel strongly against racism, it disgusts me, so it's a no brainer that I wouldn't even think twice buying a product by a known promoter of racism.
If simpleng pagkakaiba ng pananaw, I don't care much for it, I would still buy the product, I'm not melodramatic, pero if alam ko na yung pananaw nung tao na yun is harmful to others and supporting their products would mean giving them more chance or clout to spew their hatred or the like, then of course hindi ko yan bibilhin, and it depends on the situation but I might even actively oppose it in my own way.
It really depends on the situation. I don't like what China is doing now, pero good luck boycotting their products, right?
With the current situation (if it does not escalate further) The most I can do is to actively seek an alternative kung meron, but otherwise life goes on.
Just like what I do with Nestle, if may alternative then I would most likely go for it.
(He endorsed the invasion? The irresponsible pr*ck..)