My poblano peppers are still producing a lot of flowers and I think they will not have time to form mature peppers. Would it help the plant to cut those flowers off now to help speed up the growth of the present smaller peppers?
Yes, just like tomatoes, it should help redirect the plant's energy into ripening what's there rather than growing on burgeoning fruits from flowers. You can remove the leaves and stems above the existing fruits you want to keep as well, which also helps.
DISCLAIMER: Unfortunately, below is quite a speculative answer.
Plants are smart. Although it happens slowly, they detect changes in their environment and act accordingly.
In this train of thought, if you emulate autumn conditions, this should signal the plants to stop growing/flowering and make fruits instead. Just as tree fruits ripen quickly when a worm is eating them - in order to be able to soon fall to the ground serve their purpose.
Easier said than done, this is probably possible only with indoor plants. Move the pots to a darker and colder place.