PPPoE and multiple static public ip

My provider is giving internet connection with 8 public ip over PPPOE

the info he told me are something like:
public ip: 77.88.99.32/29 (netmask 255.255.255.248)
gateway: 77.88.99.33
(broadcast: 77.88.99.39 available public ip: 77.88.99.33 to 77.88.99.38
dns:8.8.8.8 (and/or others like 8.8.4.4 1.1.1.1 )
pppoe user: user@provider.it
password: password
vlan: 835

At present I am cascading 2 routers:
-the first router makes the pppoe connection
(and dynamically gets settings like that on wan:
pppoe wan ip 100.93.120.40
gateway: 100.92.0.1
dns: 77.88.128.153 , 77.88.128.154
checking with a browser my public ip gets something like: 200.201.202.5
)
its lan is configured as a network 77.88.99.32/29
and goes to the second router wan.
-the second router has multiple static ip on the wan:
77.88.99.33, 77.88.99.34, 77.88.99.35, 77.88.99.35, 77.88.99.37, 77.88.99.38
gateway: 77.88.99.33
dns:8.8.8.8 1.1.1.1 8.8.4.4
and routes to my lan (192.168.1.1)

with such configuration everything works fine,
I can set selective firewall rules that allow my servers in the lan to exit and
accept connection from the public ip of my choice

Now the question: How can I get rid of the first router?

I tried to mix the pppoe config and multi static ip in /etc/config/network
in this way unsuccessfully:

config interface 'wan'
	option force_link '0'
	option ipv6 '0'
	option delegate '0'
	option device 'eth0.835'
	option proto 'pppoe'
	option username 'user@provider.it'
	option password 'password'
	option vlanid '835'
	option disabled '0'
	option peerdns '0'
	list dns '8.8.8.8'
	list dns '1.1.1.1'
	list dns '8.8.4.4'
	option gateway '77.88.99.33'
	list ipaddr '77.88.99.34/29'
	list ipaddr '77.88.99.35/29'
	list ipaddr '77.88.99.36/29'
	list ipaddr '77.88.99.37/29'
	list ipaddr '77.88.99.38/29'

You can easily run pppoe on the second router and setup the additional wan aliases.