> Just want to confirm if "no frame-relay inverse-arp" is required on
> frame-relay subinterface as well ?

Nope,

In addition, you may want to use "no arp frame-relay" also to circumvent sending out ip address to DLCI binding information. From the router you are working on, works good for me

On the lab exam, the extra step of 'no arp frame-relay' is not necessary. The 'no frame-relay inverse-arp' is enough to stop inverse arp.

And just be aware when you use 'no arp frame-relay' that this will kill autoinstall, which is a possible exam topic.

It's necessary on physical and point-to-multipoint subinterfaces. It's not tied to interface-subinterface relationship, and it does not propagate INARP configuration from physical to logical. Whatever set of DLCI's you have attached to the physical or multipoint subinterface - by default there is an inverse arp. When you type a map command for that particular DLCI - FR INARP will be disabled, but only on that particular DLCI. Others will still have INARP enabled. If you want to disable it on all DLCIs that are terminated on the interface or a multipoint subinterface - use no frame inverse-arp under that interface. Ponit-to-point subinterface uses interface-dlci command and is out of scope of INARP.

The rule of thumb is that the command is applied wherever the IP address is assigned.

As a side note, if using multipoint subinterfaces with only static mappings then InARP does not need to be disabled.

Inverse ARP is enabled by default for all DLCI's. It's not particular to an interface type or not.
What he's getting at is two-fold.
1. If you have a sub-interface, you must ASSIGN a DLCI here, nothing gets stuck their automagically.
2. If you have a static mapping, this overrides a dynamic one when you look at the "show frame map" output.
Normally we look at having inverse arp off because the exam tells us to. If we have a full mesh of PVC's, we'd learn about connections that we should have via our physical interface (leftover/unassigned dlci's).

InARP is not enabled for a DLCI assigned to a P2P subinterface as layer 3 to layer 2 mapping is automatic for a P2P subinterface. A P2P subinterface will reply to an InARP request from another router but will not actively InARP itself.
Here are a few InARP subinterface examples:

 **********************************
 *** InARP Enabled for DLCI 102 ***
 **********************************

 interface Serial0/0

   no ip address
   encapsulation frame-relay
 !
 interface Serial0/0.1 multipoint

   ip address 10.1.1.1 255.255.255.0
   frame-relay interface-dlci 102

 **********************************
 *** InARP Enabled for DLCI 102 ***
 **********************************

 interface Serial0/0

   no ip address
   encapsulation frame-relay
   no frame-relay inverse-arp
 !
 interface Serial0/0.1 multipoint

   ip address 10.1.1.1 255.255.255.0
   frame-relay interface-dlci 102

 ***********************************
 *** InARP Disabled for DLCI 102 ***
 ***********************************
 
 interface Serial0/0

   no ip address
   encapsulation frame-relay
 !
 interface Serial0/0.1 multipoint

   ip address 10.1.1.1 255.255.255.0
   frame-relay interface-dlci 102
   no frame-relay inverse-arp

 *****************************************
 *** InARP Disabled for IP on DLCI 102 ***
 *****************************************

 interface Serial0/0

   no ip address
   encapsulation frame-relay
 !
 interface Serial0/0.1 multipoint

   ip address 10.1.1.1 255.255.255.0
   frame-relay interface-dlci 102
   no frame-relay inverse-arp IP 102

 *****************************************
 *** InARP Disabled for IP on DLCI 102 ***
 *****************************************

 interface Serial0/0

   no ip address
   encapsulation frame-relay
 !
 interface Serial0/0.1 multipoint

   ip address 10.1.1.1 255.255.255.0
   frame-relay map ip 10.1.1.1 102 broadcast

 ***********************************
 *** InARP Disabled for DLCI 102 ***
 ***********************************

 interface Serial0/0

   no ip address
   encapsulation frame-relay
 !
 interface Serial0/0.1 point-to-point

   ip address 10.1.1.1 255.255.255.0
   frame-relay interface-dlci 102

(on myths)
"no arp frame-relay" stops inverse-arp replies (it doesn't)