Absolutely! As far as I could tell, watch-only wasn't available on blockstream? (though, maybe a different story if I paired it with a Jade?) This IS a deal-breaker.
Discussion
Blockstream does have it now. But I don't think Nunchuk does.
Nunchuk (iOS) definitely has it... I use it all the time. "Recover existing wallet" reveals several options including "... using QR code" and "... using BSMS/descriptors" - each of which will generate a 'watch-only' wallet (i.e. not a 'hot' wallet).
... I'll take another look at Blockstream.
Nunchuk does support watch-only. You only need to pair a hardware signer with the app to make it watch-only.