https://github.com/vyos/vyos-1x/pull/1511

Required version for offload hardware flag nftables 0.9.9
The current version we use 0.9.8-3.1

From kernel 5.13, hardware offload is supported (if nic supports it).
Info: https://www.kernel.org/doc/html/v5.13/networking/nf_flowtable.html#hardware-offload

Not the bug, because it is internally translated to the proper value: https://github.com/vyos/vyos-1x/blob/b01f27b3bb3f4cbc6096011856d83009d0440313/data/templates/ipsec/swanctl/peer.j2#L90

PR: https://github.com/vyos/vyos-1x/pull/1509

PR https://github.com/vyos/vyatta-op/pull/57

@c-po suggested the very good idea of using a migration script to remove whitespace in this case, however, upon closer inspection, we realized that this cannot work, as a result of the binding between Python and config_tree: namely, the translation uses a split_on_whitespace function which will lose access to tag node value names containing whitespace, so the name is not manipulable through standard migration techniques. One can replace split_on_whitespace with smarter translations, however, a global solution is preferable: following discussion, the suggestion is to add a check in the legacy cstore backend to reject node names containing whitespace; the future vyconf will have this check built-in. This is the approach we will investigate.

as I remember ... it has been working by this PR:

I have NAT working with vrf in VyOS 1.4-rolling-202208290458 + custom nat offload

set interfaces ethernet eth0 address '192.168.122.14/24'
set interfaces ethernet eth1 address '192.0.2.1/24'
set interfaces ethernet eth1 vrf 'foo'
set protocols static route 192.0.2.0/24 interface eth1 vrf 'foo'
set system conntrack
set vrf name foo protocols static route 0.0.0.0/0 next-hop 192.168.122.1 interface 'eth0'
set vrf name foo protocols static route 0.0.0.0/0 next-hop 192.168.122.1 vrf 'default'
set vrf name foo table '1010'

PR https://github.com/vyos/vyos-1x/pull/1506

The same for VyOS 1.4-rolling-202208290458

vyos@r14# set interfaces ethernet eth0 offload gro
[edit]
vyos@r14# commit

PR for 1.3 https://github.com/vyos/vyos-1x/pull/1504