To test more components just use the system for more tasks; I don’t think anyone actually tests literally all components before submitting an HCL report. To do the latter (from the docs):
In order to generate an HCL report in Qubes, simply open a terminal in dom0 (Applications Menu > Terminal Emulator) and run qubes-hcl-report , where is the name of the qube in which the generated HCL files will be saved.
You are encouraged to submit your HCL report for the benefit of further Qubes development and other users. When submitting reports, test the hardware yourself, if possible. If you would like to submit your HCL report, please copy and paste the contents of the HCL Info .yml file into an email to the qubes-users mailing list with the subject HCL - , or create a post in the HCL Reports category of the forum. Pasting the contents into the email or post has the advantage that members of the mailing list and the forum can see the report without downloading and opening a file. In addition, new forum members are unable to attach files to posts.
Please include any useful information about any Qubes features you may have tested (see the legend below), as well as general machine compatibility (video, networking, sleep, etc.). Please consider sending the HCL Support Files .cpio.gz file as well. To generate these add the -s or --support command line option.
Please note: The HCL Support Files may contain numerous hardware details, including serial numbers. If, for privacy or security reasons, you do not wish to make this information public, please do not post the .cpio.gz file on a public mailing list or forum.