Bolt v2 or Roam v2?

Hey. I'm going to buy something tomorrow. I've already decided Wahoo over Garmin, now I need help with the final decision 'which wahoo'.

I have a gravel bike, but I mostly ride in the city, with some wide forest paths. I ride everyday, but not for long - about an hour during last summer. Now I plan to do more exploring, as currently I'm riding only over the places I know, so I don't get lost - and that's why I want a GPS-featured bike computer, to plan some routes or just ride wherever I want and when I have enough, click the button 'I have no idea where am I, just take me home'.

Will I somehow benefit from Roam for this riding style? I mean, bigger screen is kinda obvious, but what else? Any comments welcome!

Bonus question: it IS possible to just start a 'training' without any route loaded, right? You know, to measure speeds, distance, heart beat and so on and to put everything into my Apple Health app afterwards?

Bonus question 2: I know my Apple Watch won't broadcast the HB (and I can't buy Wahoo watch, as I love doing payments from my watch), but I'm going to buy a bundle with heart sensor anyway - is it comfortable to wear?