Hi,
Unfortunately, I cannot recommend that in any case.
If you modify the router in such way, you won't have any working routing if your product do not have any alias, if HikaShop have to generate a SEF URL with the product id and no alias ; that URL won't work. So it will be a serious bug.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.