Training with a subset of coco classes

[rehan-kinara]

Is it possible to train for a subset of coco classes without having to re-label the coco dataset. I'll make up an example - lets say I want to train a model with only person and snowboard classes. If I modify the yolov5s.yaml file to set nc: 2, and modify the coco.yaml file to include only the two classes as below, should I expect that the training system will pick up the right two classes from the 80 class coco training set and train using only that?

names:
0: person
31: snowboard

It seems to me that the alternative would be that I create a new coco-small.yaml file with:

names:
0: person
1: snowboard

and then update all the .txt in the datasets/coco/labels/train2017 folder (as well as in test and val folders) to change all label reference of 31 to 1 and remove all other labels. Potentially I might also need to remove all other images and label files which don't contain the desired classes. If possible I would like to avoid that.