I recently used the online calculator titled 'Risk of Ruin Given No Goal but a Time Constraint (Trip Ruin)' at https://www.qfit.com/blackjack-calculator-c3.htm to calculate my ROR for a 'Trip':

I used a 400 unit trip bankroll (unit value $5) and a win rate of 2.0 units per 100 hands. I figured a trip to be ten 'sessions' of 150 hands each. Assumption of 75 hands per hour x 2 hrs. = 150. My 'Trip' risk of ruin calculates to:

400 Trip Bankroll units
2.0 Win Rate in units per 100 hands
57 Standard Deviation per 100 hands: 1.14 x SqRt of 100 x $5 (unit value) = 57
1,500 Hands played (10 sessions at 150 hands each for 'Trip')
1.7% Risk of Ruin

(Please confirm that I have calculated the correct Standard Deviation of 57. I got this from BJA 3rd edition page 16.)

My question is: Does it make sense to even calculate a 'Session' ROR? You would just utilize the same calculator but use 40 'Session' bankroll units and only 150 hands? Does the small number of hands render the ROR calculation not really meaningful? I ask this because I get a ROR of 55% per session.
Or maybe ten sessions are too many? Five sessions with 80 units/session drops the ROR to 24%. However, this seems like a small number of sessions for a 'Trip'.