As the tables become crowded pen is less valuable.
With the 60% pen, what is the max number of players / hands being played before you leave?
If the pen is 75% how many hands/players until you leave?
As the tables become crowded penetration is a MORE crucial variable.
With 60% pen you can expect to see 5 rounds with 3 others (4 & dealer)
With 75% pen you can expect to see 6 rounds with 3 others (4 & dealer)
I do not suggest playing with more than that. Two is bad enough.
Normally, one should avoid playing even with two others where possible.
I cite three "others" here as a rule of thumb re: maximum crowding;
and it only holds if the Rules are (at least) good.
It is best to try to play when the tables are the least crowded.
That is a priority in DD games.
A Level Two (or better) count should be employed in a DD game
irrespective of the rules, level of penetration, etc.