Moving to Ireland without visa

Hi
I was hoping if someone can help me please.

I am a British citizen and have applied under directive Directive 2004/38/EC. I am planning to move to Ireland. I have applied for my mom’s visa to Ireland but it has been 11 months and we still haven't heard from the Irish Authorities. My question is that if I apply for UK visa and assuming my mom gets that, can I cross the common travel area into Ireland(without a visa) and register with the local Garda. On registering with the local Garda will I be issued with a temporary stay such as a stamp 4 EUFAM.

Article 5 of the Directive suggests that
"Where a Union citizen, or a family member who is not a national of a Member State, does not have the necessary travel documents or, if required, the necessary visas, the Member State concerned shall, before turning them back, give such persons every reasonable opportunity to obtain the necessary documents or have them brought to them within a reasonable period of time or to corroborate or prove by other means that they are covered by the right of free movement and residence."

The guidance above suggests that no visa is required or that the state will provide opportunities to apply for visa and won't turn back the non EU family member. Can I apply for a stamp 4 EUFAM.

Is this right? Have I interpreted it correctly? Can I apply on my arrival to Ireland for a stamp 4 EUFAM.

Please can you advise if I can do that?

This assumes mother is granted a UK visitor visa.

Any slip up or refusal once you have started along this path will reveal the intention to settle, which, in eyes of UK gov, is likely to look like an intention to circumvent UK immigration control by using SS.
New regulations are about to come into effect to close down such attempts.

Due to CTA, UK and Eire routinely share immigration-related intelligence.
Be aware the UK visit visa route will effectively be closed to you (in future) should this process fail. For example if you get to Eire via UK then face further difficulties (or refusals) with Eire documentation.

Be aware, with Brexit looming, noone starting now (or next year) will have time to go to Eire for perhaps a year and then come to reside in UK and acquire PR status in UK in the 'normal way'.