One is a 2bed/2bath completely renovated and the other is a cinder block house 2 bed/1 bath that needs minimum updates.

What type of renovations are best on a house hack if the goal is to BRRRR every year?

Best bet is to buy older homes that's renovated inside or you can renovate after purchasing and because older homes have at least 6 vehicle parking.

Currently in the planning stages, focusing on efficient renovations so we stay on schedule. 

Purchase price: $202,000 Cash invested: $75,000 For my first investment I renovated it for 5 months.

Newbie investor here, apologize in advance for the long post.
I have a house rented for $2k/month for 3 years. It is a 3/2. We are currently in the third year of rent. I have not increased their rent (although I shou...

The potential for a loan call is higher and higher with sub to the more parties you involve if that makes sense.Trying to take down four homes sub to and then do remodels to them all, and then list them on short-term rental sites, and get full permitting and ok for not just the STR, but for your renovations and all prior renovations maybe done without a permit, while on subto, sounds like a pretty big mess to me.I would consult with a sub to specialist and prepare for the potential of having all the loans called at some point.

Unlike flipping, you don’t do big renovations—just enough to get it market-ready for a fast sale.

Renovation is 46k and is being done now and roughly 4 weeks from being done.

I'd personally be a bit more conservative with the underwriting and make sure to see what the carrying costs could potential get to especially if this is a bigger renovation and not just cosmetic.