Should I only change front time of different brand?

[Pauley]

After being out of the hobby for over twenty years, I come back and find that conventional wisdom is strongly suggesting changing both tires at the same time. Now I didn't on the last tire (replaced due to holes, not wear) and at the price of some of these tires that can be a large pill to swallow. But ideally, do both and keep them in the same family.

I suspect the "replace both at the same time" mantra comes from the tire industry.

My Triumph T100 Bonneville came from the factory with a Metzler bias tire on the front and a Metzler radial on the back. (??)
I really didn't notice the difference until the time came for new tires and I started reading what was on the sidewalls.
The bike rode and handled fine. I had a set of Bridgestone's fitted and the bikes rides and handles exactly the same as before.
I'm not a hard rider, but I enjoy, shall we say, "spirited" riding

I looked around on some other forums. Bias ply rear and radial on the front is pretty common OE (especially cruisers, Triumph does it a lot). People report that mixing bias ply and radial on cars is disastrous, but not on motorcycles.

Conventional wisdom I've always heard is that mixing is a no no. This sort of changes that....