With the original bindings, it's almost unplayable using two-handed weapons, since you have to hold the grip button with your non-dominant hand to grip the two-handed weapons (even if you set the ingame grip mode to toggle, which affects your dominant hand only).
Also, you have to hold the grip button to carry items such as bombs and boosters, anyway.

and I have no idea why the devs still haven't addressed this issue, despite the fact that there are lots of people on forums asking for making the non-dominant grip being a toggle, too.
It's really a shame, and seems like they just ignoring that, and don't give a dam about it.

Since handguns and SMG did the job quite well.
But now after the release of LMG and Tommy-gun, and changing the manual reloading to have +35% damage, I decided it's time to make the workaround and make the game enjoyable.
So, I made the bindings which are now more traditional, and are almost the same as the ones in Pavlov VR and HL Alyx.

Now your both hands' grip work as toggle. To hold the double-handed weapons with two hands, you just press the grip with your non-dominant hand once to hold it, and press it again to let it go.
When your hand is empty, the trigger works also like a grip button. With that, if you're using a manual reloading, you can take your spare ammo from the ammo bag using a trigger, and c0ck the slides and bolts of weapons also using the trigger (same as in Pavlov and HLA).
Also, now you don't have to hold the grip button to carry the items (e.g. bombs/boosters/floppies). Just press the grip once to take it in the hand, and press it again to let it go.

When using the manual reloading (which gives you a +35% damage bonus), these bindings are made to be more traditional.
-The right trackpad_DOWN_button allows you to eject magazine from the weapon.
-Use the trigger to take out a new mag.
-If a weapon has a slide release (handguns/SMG), and the slide is in its back position after you emptied the magazine, you can activate it by pressing trackpad_UP_button. (of course If the "slide release button" option is enabled in the game settings). Or you can c0ck the silde manually using the trigger.
-If a weapon doesn't have a slide release (rifles, LMG) just c0ck the bolt manually as usual, using the trigger.

I left the MENU buttons operational, too, for convenience. So the weapon held in the left hand can be reloaded as in the original bindings (as well as the weapon in the right hand).

Keep in mind that the UP and DOWN trackpad buttons basically are just re-bindings of the MENU button, so if you insert the new mag in a weapon which doesn't have a slide release function, and press the UP button, the mag will be ejected, since the game works that way.

Also, if you pressed the grip button while your hand is empty, of course you need to press it again before you grab your items, since the grip now works as toggle

The only drawback of these bindings is that you can't swap two items/weapons held in both hands simultaneously.
But you still CAN swap item to your empty hand. To do that, press the grip of your empty hand, then press the grip of the hand you're holding an item in.
Still, I think the overall comfort of these bindings overcome that swapping limit.

Launch the game (as you can't browse the community bindings otherwise, for some reason).
First of all, change the "grip mode" to "manual" in the in-game settings ("gameplay" tab).
Open the SteamVR menu, pressing the Steam button on your controller, click the "controller bindings" tab.
Make sure the "active controller binding" is set to "custom".
Click on the "choose another" tab, wait for a couple of seconds, and it will load up a list of community-made bindings.
Choose the one named "Adequate controls for Vive" and click "activate".

You can also save it to your steam cloud, so if you reinstall the game, these bindings will be automatically applied.
To do this, open the SteamVR menu, click the "controller bindings",
click on "edit this binding" and then click on "save personal binding".