I don't do TA for Alt/BTC pairs for several reasons. I "rarely" trade Alt/BTC pairs. Mainly to always TRY to keep myself in a position to protect my USD and/or USDT capital.
I'm the same way, but when BTCUSD and ALT/USD pairs are
both going up, I find analyzing ALT/BTC pairs helps decide whether to position myself towards BTC or altcoins. I only like to hold altcoins if it means I'm gaining BTC.